Extremely high frequency systems and methods of operating the same

ABSTRACT

Embodiments discussed herein refer to systems, methods, and circuits for establishing EHF contactless communications links. The EHF contactless communication link may serve as an alternative to conventional board-to-board and device-to-device connectors. The link may be a low-latency protocol-transparent communication link capable of supporting a range of data rates. The link may be established through a close proximity coupling between devices, each including at least one EHF communication unit. Each EHF unit involved in establishing an EHF communication link may progress through a series of steps before data can be transferred between the devices. These steps may be controlled by one or more state machines that are being implemented in each EHF communication unit.

RELATED APPLICATION

This patent application claims the benefit of U.S. Provisional PatentApplication No. 61/799,510, filed Mar. 15, 2013, which is incorporatedby reference in its entirety.

FIELD OF THE INVENTION

The present disclosure relates to extremely high frequency (“EHF”)systems and methods for the use thereof.

BACKGROUND

Electronic devices can be “connected” together to enable data transferbetween the devices. Typically, the connection between the two devicescan be a cabled connection or a wireless connection. A cabled connectionsuch as USB (Universal Serial Bus) is typically point-to-point, andrequires mechanical connectors at each device, and a cable between thedevices. A wireless connection such as WiFi or Bluetooth can operate ina “broadcast” mode, where one device can communicate simultaneously withseveral other devices, over a RF (radio frequency) link, typically inthe range of 700 MHz-5.8 GHz. Regardless of whether the connection is acabled connection or a wireless connection, a link needs to beestablished in order to permit transfer of data to, from, and/or betweendevices. Another example of a wireless connection includes near-fieldcommunication (NFC), which can enable transfer of data from one sourceto another when both sources are in close proximity of each other.

BRIEF SUMMARY

Embodiments discussed herein refer to systems, methods, and circuits forestablishing EHF contactless communications links. The EHF contactlesscommunication link may serve as an alternative to conventionalboard-to-board and device-to-device connectors. The link may be alow-latency protocol-transparent communication link capable ofsupporting a range of data rates. The link may be established through aclose proximity coupling between devices, each including at least oneEHF communication unit. Each EHF unit involved in establishing an EHFcommunication link may progress through a series of steps before datacan be transferred between the devices. These steps may be controlled byone or more state machines that are being implemented in each EHFcommunication unit. The state machine(s) may be referred to herein asprogression of consciousness (POC) state machine(s). Each EHFcommunication unit may implement its own POC state machine in order toestablish a link with a counterpart unit. For example, if one EHFcommunication unit is functioning as a transmitter unit, its counterpartunit may be a receiver unit.

Each POC state machine may collaborate to progressively transition itsrespective communication units through a plurality of states beforeestablishing one or more contactless communications links. Thecollaboration may be necessary because the mechanism and process ofestablishing the contactless communications links, and enabling datatransfer from a host system directly onto the contactless communicationslink, is performed without the intermediary (for example) of mechanical(electrical, not RF) connectors and a cable. As such, because there isno electrical connection (except perhaps for delivering power) betweenEHF communication units, the POC state machines may rely on a “wake up”loop (sometimes referred to herein as a closed link loop) to communicatewith each other before the contactless communications link isestablished.

The wake up loop can be an inter-unit communications channel thatincludes a combination of wired and contactless paths. The wake up loopcan also include as many contactless units as necessary to provide thecommunications channel needed to establish one or more communicationslinks. The wake up loop may define upstream and downstream relationshipsamong the contactless communication units. The direction of the wake uploop may be based on the transmitter/receiver designations for each ofthe communication units. The collaborative nature of the POC statemachine may be realized in that a state change transition of a first POCstate machine may propagate around the wake up loop to cause a new statechange in each downstream POC state machine. Each state changetransition may prompt any given communications unit to notify itsimmediately downstream unit of its state change, thereby prompting thePOC state machine of that downstream unit to transition to a new state.Thus, in order for the first POC state machine to transition to a newstate, it may have to wait for state changes to propagate all the wayaround the loop, back to the first POC state machine. Thus, the firstPOC state machine may have to wait for the state machine of theimmediate upstream unit to transition to a new state, and receivenotification of that transition, before the first POC state machine cantransition to a new state. This propagation of new state changetransitions may continue to loop around the wake up loop until one ormore links are enabled to transmit data between devices.

Each communication unit executes its own POC state machine, which mayinclude several different states. In order for the POC state machine tocause a state change transition from one state to another, one or moreconditions may have to be met. Some of these conditions may be providedas notifications from source external to the communication unit or canbe generated internally within the communications unit. Externallysourced notifications or signals can be received via the transceiver orpins that make up part of an integrated circuit package of the unit.

In one embodiment, a system can include first and second devices eachincluding one or more contactless communication units. Eachcommunication unit can be operative to execute its own state machine toenable at least one contactless communications link between the firstand second devices. The state machines can collaborate to progressivelytransition their respective communication units through a plurality ofstates such that when each state machine reaches a data transport state,the at least one contactless communications link is enabled.

In another embodiment, a contactless communications receiver unit foruse in establishing a contactless communications link with a firstcontactless communications transmitter unit and for use in communicatingwith at least a second contactless communications transmitter unit viaat least one wired path is provided. The contactless communicationreceiver unit can include a plurality of pins, wherein at least one pinis used to communicate with the second transmitter unit via a wiredpath, a transducer for receiving extremely high frequency (EHF)contactless signals from the first transmitter unit, and circuitry. Thecircuitry can be operative to execute a state machine that manages aprogression of consciousness of the receiver unit as it attempts toestablish the contactless communications link, wherein the state machinetransitions through a plurality of states in response to notificationsreceived by the transducer; and drive a signal on the at least one pinused to communicate with the second transmitter unit in response to eachstate transition.

In yet another embodiment, a contactless communications transmitter unitfor use in establishing a contactless communications link with a firstcontactless communications receiver unit and for use in communicatingwith a second contactless communications transmitter unit via at leastone wired path is provided. The contactless communication transmitterunit can include a plurality of pins, wherein at least one pin is usedto communicate with the second transmitter unit via a wired path, atransducer for transmitting extremely high frequency (EHF) contactlesssignals to the first receiver unit, and circuitry. The circuitry can beoperative to execute a state machine that manages a progression ofconsciousness of the transmitter unit as it attempts to establish thecontactless communications link, wherein the state machine transitionsthrough a plurality of states in response to notifications received bythe at least one pin, and transmit EHF signals, using the transducer, inresponse to each state transition.

The operation of one or more states of the POC state machine may varydepending on whether the POC state machine is being implemented in anEHF unit configured to operate as a receiver or a transmitter. Forexample, one state may be a beacon/listen state, which may enable a unitto operate in a relatively low power mode prior to advancing throughadditional states to establish the communication link. A transmitterunit may be configured to transmit an EHF beaconing signal when in thisstate, whereas a receiver unit may be configured to listen for the EHFbeaconing signal. As a specific example, an apparatus can include an EHFtransceiver and control circuitry coupled to the EHF transceiver. Thecontrol circuitry may be operative to control establishment of an EHFcommunications link with another apparatus by executing a state machinethat transitions from state to state in response to satisfaction of anyone of a plurality of conditions, and selectively execute one of abeaconing cycle and a listening cycle based on a configuration of theapparatus, wherein the beaconing cycle is executed if the configurationis a transmitter configuration, and wherein the listening cycle isexecuted if the configuration is a receiver configuration. The controlcircuitry may execute the selected one of the beaconing cycle and thelistening cycle until the state machine transitions to a new state.

A link training state may be another state that varies depending onwhether it is being implemented in a transmitter or receiver unit. Linktraining may enable a receiver unit to calibrate itself based on a “linktraining” signals transmitted by a transmitter unit. The transmitterunit may transmit the link training signals when in the link trainingstate. The receiver unit may receive and process the link trainingsignals and calibrate itself for receiving future EHF signals from thetransmitter unit when in the link training state. As a specific example,an apparatus can include an EHF transceiver and control circuitry. Thecontrol circuitry can control establishment of an EHF communicationslink with another apparatus by executing a state machine thattransitions from state to state in response to satisfaction of any oneof a plurality of conditions, selectively execute one of a transmissionof a link training pattern and a calibration of at least one parameter,wherein the transmission of the link training pattern is executed if theconfiguration is a transmitter configuration, and wherein thecalibration of at least one parameter is executed if the configurationis a receiver configuration, and execute the selected one of thetransmission and the calibration until the state machine transitions toa new state.

A capabilities messaging state may be another state that variesdepending on whether it is being implemented in a transmitter orreceiver unit. The capabilities message may be transmitted by atransmitter unit and received by a receiver unit. The capabilitiesmessage may include information, for example, that enables thetransmitter and receiver units to validate whether they can establish alink and a protocol according to which data can be communicated. As aspecific example, an apparatus can include an EHF transceiver andcontrol circuitry. The control circuitry may control establishment of anEHF communications link with another apparatus by executing a statemachine that transitions from state to state in response to satisfactionof any one of a plurality of conditions, selectively execute one of atransmission of a capabilities message and a validation of a receivedcapabilities message, wherein the transmission of the capabilitiesmessage is executed if the configuration is a transmitter configuration,and wherein the validation of the received capabilities message isexecuted if the configuration is a receiver configuration, and executethe selected one of the transmission and the validation until the statemachine transitions to a new state.

A power savings mode state or data transport idle state may be anotherstate that varies depending on whether it is being implemented in atransmitter or receiver unit. The power savings state may enable an EHFcommunication unit to power down selective circuitry, after the EHFcommunication link has been established, when there is no data to becommunicated over the link. The transmitter unit may transmit a “keepalive” signal to the receiver unit to prevent it from timing out andexiting out of its power savings mode. The receiver unit may beperiodically turned on to monitor whether the transmitter is sending the“keep alive” signal. The transmitter and receiver units may transitionto a new state (e.g., a data transport state) when they receiveinstructions to do so. As a specific example, an apparatus can includean EHF transceiver and control circuitry. The control circuitry may beoperative to control establishment of an EHF communications link withanother apparatus by executing a state machine that transitions fromstate to state in response to satisfaction of any one of a plurality ofconditions, establish the EHF communication link with the apparatus toselectively enable one of transmission and reception of data, after theEHF communication link with the apparatus is established, monitor anabsence of data being communicated over the EHF communication link, andenter into a power savings state in response to the monitored absence ofdata being communicated over the EHF communication link until the statemachine transitions to a new state.

The communication system presented herein is unique in that thecommunication units have the flexibility to provide broadbandcommunication characteristics but at the same time consume much lesspower with a lot less complexity and cost than existing solutions.Maximizing bandwidth usage around a common carrier frequency requiresthe use of multiple communication units, each of them operating aseither a transmitter or a receiver at a certain period of time. Each ofthe units can operate in either full duplex mode or half duplex modewith the same carrier. The use of the same carrier (or substantiallysimilar carrier frequency) for different communication units in the samesystem requires spatial separation of the communication units. In orderfor the communication units in the system to communicate efficiently andeffectively with a partner system they must be able to synchronize theiroperations (and/or states). The communication units in the same systemmay communicate control information regarding the status or state usingelectrical signaling, while these same units may communicate withpartner communication units (in a different system) through EHFsignaling. Based on the requirements of a particular system, a specificcommunication unit may be powered up, based on a request from the hostsystem, and this communication unit may be responsible for initiatingthe bring up of the communication unit(s) in the same system and/or inthe partner system. The communication units may need to pass throughmultiple states, where the state transitions may partly depend on thestate of one or more of the other communication units. This requiressynchronization of the states in all communication units. In order toachieve this, the control information may pass through the communicationunits in a closed loop. In addition, data from a host system that iscommunicated through the communication units must be communicatedtransparently with little or no intervention from the host system.Control information communicated between the EHF communication unitsover an EHF link may use similar signaling characteristics as datainformation that is communicated between two host systems over the EHFlink. For example, the control information may be sent over a 60 GHzcarrier with a modulation scheme that may be similar to the modulationscheme when data information between two host systems over the EHF link.

There are several key advantages to the communication system presentedherein. By physically separating communication units in the same systemand optimizing the connection distance for contactless communication,the communication units can operate over the same EHF frequency withminimal interference through spatial separation. The communication unitsmay be simpler in design because many of the constraints from a typicalwireless system (for example, using multiple bands of frequencies forcommunication) have been relaxed or altogether removed. For example, dueto the close communication distance and minimal interference withneighboring units, the units can be designed to communicate with simplemodulation of the EHF signal and no additional error detection orcorrection circuitry. In addition, an EHF transmit unit may bephysically identical (the same silicon mask set) to an EHF receive unitand a single chip may be configured as a transmitter, a receiver, or mayalternately be programmed to be either a transmitter or a receiver. Byusing a very similar design for all the communication units, developmentand implementation costs may be reduced.

A further understanding of the nature and advantages of the embodimentsdiscussed herein may be realized by reference to the remaining portionsof the specification and the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a communications system, according to an embodiment;

FIG. 2 illustrates a communications system in which two electronicdevices communicate with one another over two or more contactlesscommunications links, according to an embodiment;

FIG. 3 is an illustrative schematic diagram of an EHF communicationunit, according to an embodiment;

FIG. 4 is an illustrative side view of an EHF communication unit,according to an embodiment;

FIG. 5 is an isometric view of an EHF communication unit, according toan embodiment;

FIG. 6 shows an illustrative flowchart showing different states of astate machine, according to an embodiment;

FIG. 7 shows a chart of illustrative state change conditionscorresponding to transition of the state machine of FIG. 6, according toan embodiment;

FIG. 8 is an illustrative timing diagram of state changes and signalstates, according to an embodiment;

FIG. 9 is an illustrative system including several EHF communicationunits arranged in a wake up loop, according to an embodiment;

FIG. 10 is another illustrative system including several EHFcommunication units arranged in a wake up loop, according to anembodiment;

FIG. 11 is yet another illustrative system including several EHFcommunication units arranged in a wake up loop, according to anembodiment;

FIG. 12 shows an illustrative schematic showing circuitry that may beused in executing the beacon listen cycle according to an embodiment;

FIGS. 13A-13D show illustrative beaconing and listening timing diagrams,each operating according to different clocking speeds, according tovarious embodiments;

FIG. 14 shows an illustrative flowchart of steps that can be performedby a transmitter unit that is beaconing according to an embodiment;

FIG. 15 shows an illustrative flowchart of steps that can be performedby a receiver unit that is listening for a beacon signal according to anembodiment;

FIG. 16 shows three different and illustrative symbols that areserialized according to an internal clock, according to an embodiment;

FIG. 17 shows an illustrative format of a capabilities message accordingto an embodiment;

FIG. 18 shows an illustrative flowchart of steps that may be taken by areceiver unit that is processing a received capabilities messageaccording to an embodiment;

FIG. 19 shows an illustrative table showing which USB modes validly worktogether and which do not, according to an embodiment;

FIG. 20 shows an illustrative lookup table that may be accessed tocompute the local code, according to an embodiment.

FIG. 21 shows illustrative actions that may be taken based oncomparisons of the received code and the local code, according to anembodiment;

FIGS. 22A-22C show different connection diagrams for EHF chipsconfigured to operate according to one of several different USB modesaccording to various embodiments;

FIGS. 23A and 23B show different connection diagrams for EHF chipsconfigured to operate according to one of several different Display Portmodes according to various embodiments;

FIG. 24 shows a connection diagram for EHF chips configured to operateaccording to a SATA or SAS data transport mode, according to anembodiment;

FIG. 25 shows a connection diagram for EHF chips configured to operateaccording to a multi-lane data transport mode, according to anembodiment;

FIG. 26 shows a connection diagram for EHF chips configured to operateaccording to an Ethernet data transport mode, according to anembodiment;

FIG. 27 shows a connection diagram for EHF chips configured to operateaccording to a I2S data transport mode, according to an embodiment;

FIGS. 28A-28C show different connection diagrams for EHF chipsconfigured to operate according to a GPIO or I2C transport modeaccording to various embodiments;

FIG. 29 shows a connection diagram for EHF chips configured to operateaccording to a generic data transport mode that does not require aprogression of consciousness, according to an embodiment;

FIG. 30 shows an illustrative flowchart of steps that may be taken by atransmitter unit during a data transport idle state, according to anembodiment;

FIG. 31 shows an illustrative flowchart of steps that may be taken by areceiver unit during a data transport idle state, according to anembodiment;

FIG. 32 shows illustrative timing diagrams of a data transport idle keepalive cycle, according to an embodiment;

FIG. 33 illustrates a communications system wherein two electronicdevices communicate with one another over a contactless communicationslink, according to an embodiment;

FIG. 34 shows an illustrative timing diagram, according to anembodiment;

FIG. 35 shows an illustrative flowchart of steps that may be taken by anEHF communication unit that is operating primarily as a transmitter unitaccording to an embodiment; and

FIG. 36 shows an illustrative flowchart of steps that may be taken by anEHF communication unit that is operating primarily as a receiver unitaccording to an embodiment.

DETAILED DESCRIPTION

Illustrative embodiments are now described more fully hereinafter withreference to the accompanying drawings, in which representative examplesare shown. Indeed, the disclosed communication system and method may beembodied in many different forms and should not be construed as limitedto the embodiments set forth herein. Like numbers refer to like elementsthroughout.

In the following detailed description, for purposes of explanation,numerous specific details are set forth to provide a thoroughunderstanding of the various embodiments. Those of ordinary skill in theart will realize that these various embodiments are illustrative onlyand are not intended to be limiting in any way. Other embodiments willreadily suggest themselves to such skilled persons having the benefit ofthis disclosure.

In addition, for clarity purposes, not all of the routine features ofthe embodiments described herein are shown or described. One of ordinaryskill in the art would readily appreciate that in the development of anysuch actual embodiment, numerous embodiment-specific decisions may berequired to achieve specific design objectives. These design objectiveswill vary from one embodiment to another and from one developer toanother. Moreover, it will be appreciated that such a development effortmight be complex and time-consuming but would nevertheless be a routineengineering undertaking for those of ordinary skill in the art havingthe benefit of this disclosure.

In today's society and ubiquitous computing environment, high-bandwidthmodular and portable electronic devices are being used increasingly.Security and stability of communication between and within these devicesis important to their operation. In order to provide improved securehigh-bandwidth communications, the unique capabilities of wirelesscommunication between electronic devices and between sub-circuits withineach device may be utilized in innovative and useful arrangements.

Such communication may occur between radio frequency communicationunits, and communication at very close distances may be achieved usingEHF frequencies (typically, 30-300 GHz) in an EHF communication unit. Anexample of an EHF communications unit is an EHF comm-link chip.Throughout this disclosure, the terms comm-link chip, and comm-link chippackage are used to refer to EHF antennas embedded in IC packages.Examples of such comm-link chips are described in detail in U.S. PatentApplication Publication Nos. 2012/0263244; and 2012/0307932, both ofwhich are hereby incorporated in their entireties for all purposes.Comm-link chips are an example of a communication device, also referredto as communication unit, whether or not they provide wirelesscommunication and whether or not they operate in the EHF frequency band.

The acronym “EHF” stands for Extremely High Frequency, and refers to aportion of the electromagnetic (EM) spectrum in the range of 30 GHz to300 GHz (gigahertz). The term “transceiver” may refer to a device suchas an IC (integrated circuit) including a transmitter (Tx) and areceiver (Rx) so that the integrated circuit may be used to bothtransmit and receive information (data). Generally, a transceiver may beoperable in a half-duplex mode (alternating between transmitting andreceiving), a full-duplex mode (transmitting and receivingsimultaneously), or configured as either a transmitter or a receiver. Atransceiver may include separate integrated circuits for transmit andreceive functions. The terms “contactless,” “coupled pair,” and “closeproximity coupling” as used herein, refer to the implementingelectromagnetic (EM) rather than electrical (wired, contact-based)connections and transport of signals between entities (such as devices).As used herein, the term “contactless” may refer to a carrier-assisted,dielectric coupling system which may have an optimal range in the zeroto five centimeter range. The connection may be validated by proximityof one device to a second device. Multiple contactless transmitters andreceivers may occupy a small space. A contactless link established withelectromagnetics (EM) may be point-to point in contrast with a wirelesslink which typically broadcasts to several points.

The RF energy output by the EHF transceivers described herein may bedesigned to adhere to various requirements mandated by one or moregovernments or their agencies. For example, the FCC may promulgaterequirements for certification for transmitting data in a RF frequencyband.

“Standards” and related terms such as “Standards-based”,“Standards-based interfaces”, “Standards-based protocol”, and the likemay refer to wired interface standards which may include but are notlimited to USB, DisplayPort (DP), Thunderbolt, HDMI, SATA/SAS, PCIe,Ethernet SGMII, Hypertransport, Quickpath, 125 GPIO, I2C and theirextensions or revisions.

FIG. 1 illustrates a communications system 100 wherein two electronicdevices 102 and 122 may communicate with one another over a contactlesscommunications links 150. Data may be transferred in at least onedirection, from first device 102 which may be regarded as a “source” forsending the data to be transferred, to second device 122 which may beregarded as a “destination” for receiving the data which is transferred.With reference to FIG. 1, the transfer of data from first device 102 tosecond device 122 may be described. However, it should be understoodthat data may alternatively or additionally be transferred from seconddevice 122 (acting as a “source” for sending the data) to first device102 (acting as a “destination” for receiving the data), and that ofteninformation may be exchanged in both directions between devices 102 and122 during a given communications session.

For illustrative clarity, devices 102 and 122 will be described as“mirror images” of one another, but it should be understood that the twodevices 102 and 122 may be different than each other. For example, oneof the devices may be a laptop computer, the other device may be amobile phone. Some examples of electronic devices which may benefit fromthe techniques disclosed herein may include cell phones (or handsets, orsmart phones), computers, docks (docking stations), laptops, tablets, orcomparable electronic device, to name but a few.

First electronic device 102 may include a host system 104 and acontactless communication unit (which may be referred to as “smart”contactless connector, a communication subsystem, “smart connector”,“contactless connector”, or simply “connector”) 106. The unit 106associated with the electronic device may be generally capable ofperforming at least one of establishing and managing operation ofcontactless link 150 with unit 126, of second device 122, monitoring andmodifying data passing through unit 106 onto link 150, and interfacingwith and providing application support for host system 104. Thesefunctions of unit 106, with regard to interacting with link 150, thedata and host system 104 may be described and elaborated upon anddiscussed in greater detail hereinbelow (or elsewhere in thisdisclosure).

Unit 106 associated with first device 102 may include some or all of thefollowing elements: electrical interface 108, processor 110 andassociated memory 112, control circuits 114, measurement circuits 116,and one or more transceivers 118. The operation of these variouselements (110-118) may be described and elaborated upon and discussed ingreater detail hereinbelow (or elsewhere in this disclosure).

Second electronic device 122 may include host system 124 and acontactless communication unit (which may be referred to as “smart”contactless connector, or “communication unit”, or “smart connector”, or“contactless connector”, or simply “connector”) 126. Connector 126associated with the electronic device may be generally capable ofestablishing and managing operation of contactless link 150 with unit106, of first device 102, monitoring and modifying data passing thoughthe unit 126 onto link 150, and interfacing with and providingapplication support for host system 124. These functions of unit 126,with regard to interacting with link 150, the data and the host system124 may be described and elaborated upon and discussed in greater detailhereinbelow (or elsewhere in this disclosure).

Unit 126 associated with second device 122 may include some or all ofthe following elements an electrical interface 128, processor 130 andassociated memory 132, control circuits 134, measurement circuits 136,and one or more transceivers 138. The operation of these variouselements (130-138) may be described and elaborated upon and discussed ingreater detail hereinbelow (or elsewhere in this disclosure).

Units 106 and 126 may operate without intervention from the hostprocessors (in the host systems 104 and 124, respectively), and may takecontrol of the host system 104 and 124, respectively, or portionsthereof. Units 106 and 126 may open/activate applications, returnstatus/power levels, connection parameters, data types, info ondevices/systems that are connected, content info, amount and type ofdata being transferred, including device configuration based onconnection type, link management, quota information, channel control,and the like.

The dashed-line rectangles shown (in the figure) around the units 106and 126 may simply represent “partitioning” of functions, separating(distinguishing) units 106 and 126 from host system 104 and 124,respectively. The antennae shown (symbolically) outside of thedashed-line rectangles may be considered to be within the functionalblocks of units 106 and 126, but may be disposed either internal orexternal to a communications chip constituting the contactlessconnector. The dashed-line rectangles shown (in the figure) around units106 and 126 may also represent non-conducting barriers (housings,enclosures, or the like, not shown), such as of plastic or acrylicenclosing units 106 and 126 or entire devices 102 and 122, respectively,as described hereinabove.

Electrical interfaces 108 and 128 may include communicationsport(s)/channel(s) to communicate with host systems 104 and 124,respectively. Host systems 104 and 124 may have their own processors andassociated circuitry (not shown).

Processors 110 and 130 may be embedded microprocessors, ormicrocontrollers, or state machines, may run management OS for theconnection, and may have built-in authentication/encryption engines.Processors 110 and 130, either alone or in combination with otherelements presented herein, may be operative to manage the communicationslink, to monitor data passing through the units and over thecommunications link, or to provide application support for the hostsystem, or to execute one or more state machines, or variations thereofas may become evident from the several functional descriptions set forthherein. In a broader sense, units 106 and 126 are capable of performingone of more of (at least one of) the various functions described herein.

Memory 112 and 132 may be RAM (random access memory), NVRAM(non-volatile RAM), or the like, and may include registers containingconfiguration, status, permissions, content permissions, keys forauthentication/encryption, and the like.

Control circuits 114 and 134 may include any suitable circuitry capableof monitoring the state of the link and/or actively appending to orchanging data concurrently (“on-the-fly”) as it goes through unit 106 or126, respectively.

Measurement circuits 116 and 136 may include any suitable circuitrycapable of observing (monitoring) the connection state/status, theconnection type and the data being transmitted. Sensors (not shown) maybe included to monitor signal strength, ambient environmentalconditions, and the like. Signal-to-noise ratio can be used as anindicator of signal quality.

Transceivers 118 and 138 may include any transceivers (and associatedtransducers or antennas) suitable for converting between electricalsignals (for the host system) and electromagnetic (EM) signals (for thecontactless communications link), such as have been describedhereinabove. Transceivers 118 and 138 may each be a half-duplextransceiver which can asynchronously convert a baseband signal into amodulated EHF (extremely high frequency) carrier at 30-300 GHz, orhigher, such as 60 GHz carrier frequency, which is radiated from aninternal or external antenna (shown schematically only), or can receiveand demodulate the carrier and reproduce the original baseband signal.The EHF carrier may penetrate a wide variety of commonly-usednon-conductive materials (glass, plastic, etc.).

It should be understood that if only one-way communication is required,such as from first device 102 to second device 122, transceiver 118could be replaced by a transmitter (Tx) and transceiver 138 could bereplaced by a receiver (Rx).

Transmit power and receive sensitivity for transceivers 118 and 138 maybe controlled to minimize EMI (electromagnetic interference) effects andsimplify FCC certification, if required.

Transceivers 118 and 138 may be implemented as IC chips comprising atransmitter (Tx), a receiver (Rx) and related components. Transceiverchip(s) may be packaged in a conventional manner, such as in BGA (ballgrid array) format. The antenna may be integrated into the package, ormay be external to the package, or may be incorporated onto the chipitself. An exemplary unit 106, 126 may include one, two, or moretransceiver chips. Some features or characteristics of the transceivers118 and 138 may include low latency signal path, multi-gigabit datarates, link detection and link training. The signals transmitted bytransceivers 118 and 138 may be modulated in any suitable manner toconvey the data being transferred from one device to the other device,some non-limiting examples of which are presented herein. Modulation maybe OOK (on/off keying), ASK, PSK, QPSK, QAM or other similar simplemodulation techniques. Signals may be encoded and packetized andtransmitted by one transceiver (such as 118), and received andunpacketized and decoded by another transceiver (such as 138).Out-of-band (OOB) signaling or other suitable techniques may be used toconvey information other than or related to the data being transferredbetween the two devices.

Transceivers 118 and 138, or individual transmitters and receivers,which may be implemented as chips, may be factory-serialized, so thatthe chips and their transmissions may be ‘tagged’ (fingerprinted), whichmay enable a later forensic analysis to be performed for digital rightsmanagement (DRM). For example, protected (premium) content could befreely (unimpeded) transferred from one device to another, but thetransaction could be traced to the specific devices involved, so thatthe participants in the transaction can be held accountable (such as,billed). Premium protected content may be modified, data appendedthereto, and can be logged with chip ID, user ID, or by other means.

Communications link 150 may be a “contactless” link, and the first andsecond units 106 and 126 may be “contactless” connectors, as describedherein. Differences between units 106 and 126 disclosed herein andconventional mechanical connectors may be immediately apparent, and maybe described herein. The units may be considered to be communicationsubsystems of a host device. In this regard, differences between thecontactless connectors 106 and 126 disclosed herein and controllers suchas Ethernet (Standard) controllers may not be immediately apparent inthat both may handle data flow between a host system and acommunications link. However, a distinction between the contactlessconnectors disclosed herein and exemplary Standards controllers is thatthe contactless connectors disclosed herein both set up the contactlesscommunications link and transfer data from a host system directly ontothe contactless communications link, without the intermediary (forexample) of mechanical (electrical, not RF) connectors and a cable.Further distinctions may be made in the way that the contactlessconnectors disclosed herein are capable of operating independently andtransparently from the host system, without requiring host awareness orinteraction.

Data transfer between electronic devices 102 and 122 may be implementedover a “contactless” radio frequency (RF) electromagnetic (EM)communications link (interface) 150, which is handled substantiallyentirely by the units 106 and 126 of first and second devices 102 and122, respectively. Signals flowing between the devices 102 and 122occurs electromagnetically over a non-electrical (dielectric) mediumsuch as an air gap, waveguide, plastics (polyethylene, thermoplasticpolymers, polyvinylidene difluoride, fluoropolymers, ABS, and otherplastics), including combinations of these materials The EHF signal canpass through other dielectric materials such as cardboard. The EHFsignal can pass through a series of different dielectric materialsand/or waveguides.

Due to the high data rate enabled by the EHF contactless communication,large data files, such as movies, audio, device images, operatingsystems, and the like may be transferred in very short periods of timein contrast with existing technologies such as NFC. As an example, a 1Gigabyte data file may be transferred in as little as 2 seconds. Theelectromagnetic communication may typically be over an air gap may belimited to a short range, such as 0-5 cm. A dielectric medium such as adielectric coupler, may be used to extend the range of the contactlesslink between the devices 102 and 122 to several centimeters (cm),meters, or more.

The communications link may include a dielectric medium that may includeone or more of an air gap, a waveguide, and plastics. Alternatively, thecommunications link may be a slot antenna in a conductive medium, theslot antenna directing the contactless connectivity in a desireddirection. A device (at least the contactless connector) may besubstantially fully enclosed by a conductive medium other than at alocation where it is desired to emit and receive EHF radiation from apartner device (at least the contactless connector thereof) which mayalso be similarly substantially fully enclosed by a conductive medium.

It should be understood that in this, and any other embodiments ofcontactless links discussed herein, an overall communications system maybe implemented as a combination of contactless and physical links.Furthermore, some of the techniques described herein may be applied totransferring data over a physical link, such as a cable and connectors.Similarly, some of the techniques described herein may be applied totransferring data over a wireless link, such as WiFi or Bluetooth. Inthe main, hereinafter, the use of a contactless link for transferringdata between the two devices will be described.

One or both of devices 102 and 122 may have two (or more) transceivers.Having two (or more) transceivers may support a feedback loop, latency,changes, full duplex operation, and simultaneously establishing a secondcommunications link (such as for communicating with the host system). Anexemplary “data flow” may proceed as follows. Data originating from hostsystem 104 (or data originating at unit 106) may be provided by unit106, via its transceiver 118, onto the communications link 150. The datapasses through (or over) communications link 150. Data received from thecommunications link 150 by the transceiver 138 of unit 126 may beprovided to host system 124 (or may remain in with unit 126). Data mayflow in the reverse direction, from host system 124 via unit 126 (ororiginating at unit 126) onto the contactless link 150 to unit 106 whichmay pass the data to the host system 104.

FIG. 2 illustrates a communications system 200 wherein two electronicdevices 210 and 220 may communicate with one another over two or morecontactless communications links, according to an embodiment. System 200may be similar to system 100 in many respects, but for illustrative andsimplified discussion purposes, shows that each device includes two EHFcommunication units. Moreover, any EHF communication unit in system 200may be the same or substantially the same as any EHF communication unitin system 100. As such, a more simplified representation of units 106and 126 are shown in FIG. 2. If desired, each device can include three,four, five, or more EHF communication units. First device 210 mayinclude EHF communication unit 212, EHF communication unit 214, and hostsystem 216. One or more wired paths 213 may directly connect EHFcommunication units 212 and 214 together. Host system 216 maycommunicate with EHF communication units 212 and 214. In someembodiments, EHF communication units 212 and 214 may communicate witheach other through host system 216. In other embodiments, host system216 may be able to drive a signal on at least one of wired paths 213.Similarly, second device 220 may include EHF communication unit 222, EHFcommunication unit 224, and host system 226. One or more wired paths 223may directly connect EHF communication units 222 and 224 together. Hostsystem 226 may communicate with EHF communication units 222 and 224. Insome embodiments, EHF communication units 222 and 224 may communicatewith each other through host system 226. In other embodiments, hostsystem 226 may be able to drive a signal on at least one of wired paths223. Host systems 216 and 226 may be similar to host systems 104 and124, both of which include circuitry specific to their respectivedevices and thereby enable devices 210 and 220 to operate for theirintended functionality.

In some embodiments, each of EHF communication units 212, 214, 222, and224 can be the same as EHF communication unit 106 or 126, discussedabove. As such, EHF communication units 212, 214, 222, and 224 includetransceivers capable of being configured to transmit and/or receive EHFsignals. For example, in one approach, units 212 and 224 can beconfigured to receive EHF signals and units 214 and 222 can beconfigured to transmit EHF signals. Thus, in this approach, acontactless communications link 230 may exist between EHF communicationunits 212 and 222, and contactless communications link 232 may existbetween EHF communication units 214 and 224. As shown, units 212 and 222may work together as a coupled pair of units that communicate via link230, and units 214 and 224 may work together as another coupled pair ofunits that communicate via link 232. If one or more additional coupledpairs of units were to be included in system 200, then additionalcommunications links would also exist.

Embodiments discussed herein refer to systems, methods, and circuits forestablishing the contactless communications links among coupled pairs ofEHF communication units. In order for devices 210 and 220 to communicatewith each other using one or more contactless links, the EHF unitsresponsible for establishing those links may have to progress through aseries of steps before data can be transferred between the devices.These steps may be controlled by one or more state machines that arebeing implemented in each contactless communication unit. Collectively,regardless of whether one or more state machines are used to establish alink, the state machine(s) may be referred to herein as a progression ofconsciousness (POC) state machine. Each contactless communication unitmay implement its own POC state machine in order to establish a linkwith a counterpart unit.

Each POC state machine may collaborate to progressively transition theirrespective communication units through a plurality of states beforeenabling one or more contactless communications links. The collaborationmay be necessary because the mechanism and process of establishing thecontactless communications links, and enabling data transfer from a hostsystem directly onto the contactless communications link, is performedwithout the intermediary (for example) of mechanical (electrical, notRF) connectors and a cable. As such, because there is no electricalconnection (except perhaps for delivering power) between, for example,units 212 and 222, the POC state machines may rely on a “wake up” loop(sometimes referred to herein as a closed link loop) to communicate witheach other before the contactless communications link is established. Insome embodiments, the POC state machine may collaborate with the statemachine of the host system. For example, an entry into power up or powerdown state may be directed by the host system.

The wake up loop can be an inter-unit communications channel thatincludes a combination of wired and contactless paths. The wake up loopcan also include as many contactless units as necessary to provide thecommunications channel needed to establish one or more communicationslinks. In some embodiments, only two units can be used. A wake up loopusing only two units may require selective gating of each unit'stransceiver so that a loop can exist over a single contactless path. Inother embodiments, as that shown in FIG. 2, at least four units can beused to define a wake up loop. As shown, the wake up loop in system 200can include unit 212, wired path 213, unit 214, contactless path 232,unit 224, wired path 223, unit 222, and contactless path 230. Thus, inthis arrangement, although units 212 and 222 may be operative toestablish link 230, they may depend on the wake up loop to communicatewith each other to establish link 230. For example, assume that unit 222operates as a transmitter unit and unit 212 operates as a receiver unit.Since unit 222 is a transmitter unit, it may be able to transmit signalsdirectly with unit 212 via link 230. However, because unit 212 isoperating as a receiver unit, it is not able to transmit signals to unit222 via the same link 230. Instead, unit 212 may communicate with unit222 indirectly using a combination of wired and contactless paths in thewake up loop. In this example, unit 212 may communicate with unit 222via wired path 213, unit 214, link 232, unit 224, and wired path 223.Thus, in order for a coupled pair to communicate signals back and forthamong each other, the coupled pair may leverage the wake up loop (e.g.,the wired paths connected to another coupled pair, and the contactlesspath existing between that other coupled pair).

The wake up loop may define upstream and downstream relationships amongthe contactless communication units. The direction of the wake up loopmay be based on the transmitter/receiver designations for each of thecommunication units. For example, in system 200, assuming units 214 and222 are transmitters, and units 212 and 224 are receivers, the wake uploop may progress in a clockwise direction. In a clockwise oriented wakeup loop, unit 214 may be immediately downstream from unit 212, and unit222 may be immediately upstream from unit 212. As another example,assuming units 214 and 222 are receivers, and units 212 and 224 aretransmitters, the wake up loop may progress in a counter-clockwisedirection.

The collaborative nature of the POC state machine may be realized inthat a state change transition of a first POC state machine maypropagate around the wake up loop to cause a new state change in eachdownstream POC state machine. Each state change transition may promptany given communications unit to notify its immediately downstream unitof its state change, thereby prompting the POC state machine of thatdownstream unit to transition to a new state. Thus, in order for thefirst POC state machine to transition to a new state, it may have towait for state changes to propagate all the way around the loop, back tothe first POC state machine. Thus, the first POC state machine may haveto wait for the state machine of the immediate upstream unit totransition to a new state, and receive notification of that transition,before the first POC state machine can transition to a new state. Thispropagation of new state change transitions may continue to loop aroundthe wake up loop until one or more links are enabled to transmit databetween devices. In order to begin the wake up loop, a host system mayassert one or more signals to one or more EHF communications units. ThePOC state machines of the targeted EHF communication units maytransition to a new state or may begin beaconing or listening asdescribed below in response to the signals from the host system.

As discussed above, each communication unit executes its own POC statemachine. That POC state machine may include several different states(discussed below). In order for the POC state machine to cause statechange transitions from one state to another, one or more conditions mayhave to be met. Some of these conditions may be provided asnotifications from sources external to the communication unit or can begenerated internally within the communications unit. Externally sourcednotifications can be received via the transceiver or pins that make uppart of an integrated circuit package of the unit. In order to provide abasis for discussing where such notifications can be received andgenerated, reference is now made to FIGS. 3-5.

FIG. 3 shows an illustrative block diagram of EHF contactlesscommunication unit 300 according to an embodiment. Unit 300 may be, forexample, an integrated circuit including several pins. As shown, unit300 may include pins 301-313, EHF transceiver 320, antenna 325,high-speed circuitry 330, low-speed circuitry 340, receiver slicer andpost-amp circuitry 350, transmitter pre-processing circuitry 352, powermanagement circuitry 360, and logic and control circuitry 370. Logic andcontrol circuitry 370 may include several modules, which may representhardware and/or software components for operating specific functions ofunit 300. For example, logic and control circuitry may include logicmodule 372, interface mode module 380, and beacon/listen module 390.V_(DD) pin 301 may be coupled to an external source for powering unit300. V_(DD2) pin 307 may be an optional pin as shown, or it may beinternally bonded to V_(DD) pin 301. Ground pin 306 may be coupled to aground source (not shown). High-speed circuitry 330, low-speed circuitry340, receiver slicer and post-amp circuitry 350, and transceiverpre-processing 352 may be referred to collectively herein as basebandcircuitry. Power management circuitry 360, logic and control circuitry370, logic module 372, interface module 380, and beacon/listen module390 may be referred to herein as control circuitry.

High-speed differential (“HSD”) pins 302 and 303 may function as inputand/or output pins for high-speed circuitry 330. High-speed circuitry330 may be operative to process signals according to various protocols,including, for example, USB, SATA, PCIe, and Display Port. Low-speeddifferential (“LSD”) pins 304 and 305 may function as input and/oroutput pins for low-speed circuitry 340. Low-speed circuitry 340 may beoperative to process signals according to various protocols, includingfor example USB high-speed/full-speed, Display Port Auxiliary, I2S,GPIO, I2C, and other low speed signaling schemes. In some embodiments,low-speed circuitry 340 may process protocols that operate at speedsthat are slower relative to protocols processed by high-speed circuitry340. In some embodiments, high and low speed circuitry 330 and 340 mayprovide baseband functionality.

Transceiver 320 may be coupled to antenna 325, high-speed circuitry 330,and low-speed circuitry 340. Transceiver 320 may include an EHF receiver321 and an EHF transmitter 322. Unit 300 may be designated to operate aseither a transmitter unit (in which case EHF transmitter 322 is selectedfor operation) or a receiver unit (in which case EHF receiver 321 isselected for operation). EHF receiver unit 321 may be coupled tohigh-speed circuitry 330 via receiver slicer and post-amp circuitry 350.Receiver slicer and post-amp circuitry 350 may assist high-speedcircuitry 330 in processing high-speed protocols. The output of EHFreceiver 321 or receiver slicer and post-amp circuitry 350 may becoupled to circuitry 340. Circuitry 340 may operate as a bidirectionaldata transfer block either in half-duplex mode or full-duplex modeacting as buffer between the data being transferred between electricalinterface 304/305 and EHF transceiver 320. EHF transmitter 322 may becoupled to high-speed circuitry 330 and low-speed circuitry 340.

Logic and control circuitry 370 may be operative to control operation ofunit 300 according to various embodiments. In some embodiments, logicmodule 372 may operate a progression of consciousness state machine thatmanages the establishment of a contactless link with another unit. Logicand control circuitry 370 may communicate with transceiver 320,high-speed circuitry 330, low-speed circuitry 340, and receiver slicerand post amp circuitry 350.

Logic and control circuitry 370 can use interface module 380 to operateunit 300 in a serial interface control mode, such as when using theserial peripheral interface protocol (SPI). The serial interface controlmode may be used to perform various diagnostic tests, such as alaboratory and automatic test equipment (“ATE”) test, and to performadvanced control and manufacturing trim. When unit 300 is not operatingin the serial interface control mode, it may operate in a pin-strappedcontrol mode. In this mode, the operating state of unit 300 iscontrolled by static settings of one or more of pins 301-313, andparticularly with respect to settings of pins 308-313. Logic and controlcircuitry 370 may be coupled to pins 308-313, and may be configured tooperate unit 300 based on signals provided on one or more of pins308-313. Pins 308-313 may be referred to herein collectively asconfiguration and control pins, and have pin designations CP1-CP6. Someof the pins may act as status or indicator pins, and some may serve asinput pins, output pins, or both input and output pins.

The configuration and control pins may indicate which data transportmode should be used for transporting data across a contactlesscommunication link established using unit 300. In particular, CP2 pin309 may be a first data transport selection pin, and CP3 pin 310 may bea second data transport selection pin. Pins 309 and 310 may be set to alogic HIGH, logic LOW, or left to FLOAT. CP1 pin 308 may function asanother data transport selection pin or as an identification pin. CP1pin 308 may be driven to one of HIGH, LOW, and FLOAT with a high/low/Zdriver. When CP1 pin 308 is left to FLOAT, the impedance on the pin maybe used to identify which data transport should be used.

CP4 pin 311 may be set to specify whether unit 300 is to function in atransmitter mode, a receiver mode, or a control mode, which wouldutilize interface circuitry 380. CP5 pin 312 may be used for inter unitcommunications. For example, unit 300 may be able to communicate withanother unit (not shown) via CP5 pin 312. Referring briefly to FIG. 2,wired path 213 may be coupled to respective CP5 pins on both units 212and 214. This inter unit communication may be used to establish wiredportions of a wake up loop among a set of contactless units. CP6 pin 313can be used as part of a beacon/listen state machine, which may becontrolled by beacon/listen module 390, and which also may be a subsetof the POC state machine. For example, when CP6 pin 313 is driven HIGH,communication unit 300 may be turned ON and begins operating accordingto the beacon/listen state machine.

Beacon/Listen module 390 may include circuitry for operating abeaconing/listening state machine. Depending on whether unit 300 isconfigured to operate as a transmitter or a receiver dictates whetherthe beacon/listen state machine operates a beacon state machine or alisten state machine. The beacon state machine may be implemented whenunit 300 is configured for operation as a transmitter and the listenstate machine may be implemented when unit 300 is configured foroperation as a receiver. Beacon/Listen module 390 may use relatively lowpower consuming circuitry when power is applied to V_(DD) pin 301. Itspower consumption may be relatively low compared to the powerrequirements of logic module 372. As will be explained in more detailbelow, unit 300 may initially cycle through the beaconing/listeningstate machine portion of the POC state machine to conserve power, andthen operate according to a relatively higher power consuming portion ofthe POC state machine.

Power management circuitry 360 may be operative to regulate powerreceived via pin 301 and provide regulated power at one or moredifferent power levels, including appropriate voltage levels, tocomponents within unit 300. For example, power management circuitry 360may provide power to beacon/listen circuitry 390 when unit 300 isoperating according to the beaconing/listening state machine.

FIG. 4 is a side view of an exemplary EHF communication circuit 400showing a simplified view of some structural components. As illustrated,the communication circuit may include an integrated circuit package 401that includes die 402 mounted on connector printed circuit board (PCB)403, a lead frame (not shown), one or more conductive connectors such asbond wires 404, a transducer such as antenna 406, and an encapsulatingmaterial 408.

Die 402 may include any suitable structure configured as a miniaturizedcircuit on a suitable die substrate, and is functionally equivalent to acomponent also referred to as a “chip” or an “integrated circuit (IC).”The die substrate may be formed using any suitable semiconductormaterial, such as, but not limited to, silicon. Die 402 may be mountedin electrical communication with the lead frame. The lead frame (similarto lead frame 518 of FIG. 5) may be any suitable arrangement ofelectrically conductive leads configured to allow one or more othercircuits to operatively connect with die 402. The leads of the leadframe may be embedded or fixed in a lead frame substrate. The lead framesubstrate may be formed using any suitable insulating materialconfigured to substantially hold the leads in a predeterminedarrangement.

Further, the electrical communication between die 402 and leads of thelead frame may be accomplished by any suitable method using conductiveconnectors such as, one or more bond wires 404. Bond wires 404 may beused to electrically connect points on a circuit of die 402 withcorresponding leads on the lead frame. In another embodiment, die 402may be inverted and conductive connectors including bumps, or die solderballs rather than bond wires 404, which may be configured in what iscommonly known as a “flip chip” arrangement. Transducer 406 may be anysuitable structure configured to convert between electrical andelectromagnetic signals. In some embodiments, transducer 406 is anantenna. Transducer 406 in conjunction with the circuitry on die 402 maybe configured to operate in an EHF spectrum, and may be configured totransmit and/or receive electromagnetic signals, in other words as atransmitter, a receiver, or a transceiver. In an embodiment, transducer406 may be constructed as a part of the lead frame. IC package 401 mayinclude more than one transducer 406. In another embodiment, transducer406 may be separate from, but operatively connected to die 402 by anysuitable method, and may be located adjacent to die 402. For example,transducer 406 may be connected to die 402 using bond wires (similar to520 of FIG. 5). Alternatively, in a flip chip configuration, transducer406 may be connected to die 402 without the use of the bond wires (see520). In other embodiments, transducer 406 may be disposed on die 402 oron PCB 412.

Encapsulating material 408 may hold the various components of IC package401 in fixed relative positions. Encapsulating material 408 may be anysuitable material configured to provide electrical insulation andphysical protection for the electrical and electronic components of theIC package. For example, encapsulating material 408 may be a moldcompound, glass, plastic, or ceramic. Encapsulating material 408 may beformed in any suitable shape. For example, encapsulating material 408may be in the form of a rectangular block, encapsulating all componentsof the IC package except the unconnected leads of the lead frame. One ormore external connections may be formed with other circuits orcomponents. For example, external connections may include ball padsand/or external solder balls for connection to a printed circuit board.

IC package 401 may be mounted on a connector PCB 403. Connector PCB 403may include one or more laminated layers 412, one of which may be a PCBground plane 410. PCB ground plane 410 may be any suitable structureconfigured to provide an electrical ground to circuits and components onthe IC package. With the placement of the ground layer, at anappropriate distance from the antenna, the electromagnetic radiationpattern may be directed outwards from the substrate.

FIG. 5 is a simplified isometric view of another example of acommunication circuit 500 showing some structural components. Asillustrated, communication circuit 500 may include an IC package 501that may in turn include a die 502, a lead frame 518, one or moreconductive connectors such as bond wires 504, a transducer 506, one ormore bond wires 520, and an encapsulating material 508. Die 502, leadframe 518, one or more bond wires 504, transducer 506, bond wires 520,and an encapsulating material may be functionality similar to componentssuch as die 402, bond wires 404, transducer 404, and encapsulatingmaterial 408 of IC package 401, respectively, as described in FIG. 4.Further, communication circuit 500 may include a connector PCB similarto PCB 403, not shown).

In FIG. 5, it may be seen that die 502 is encapsulated in encapsulatingmaterial 508, along with the bond wires 504 and 520. In this embodiment,the IC package may be mounted on the connector PCB. The connector PCBmay include one or more laminated layers, one of which may be a PCBground plane. The PCB ground plane may be any suitable structureconfigured to provide an electrical ground to circuits and components onthe PCB. With the placement of the ground layer, at an appropriatedistance from the antenna, the electromagnetic radiation pattern may bedirected outwards from the substrate.

Referring now collectively to FIGS. 3, 6, 7, 8, and 9 the progression ofconsciousness state machine of an EHF communication unit is discussed.FIG. 6 shows an illustrative flowchart of various states of the POCstate machine according to an embodiment. Each state change transitionis associated with a number. That number corresponds to one or moreconditions that need to be met to satisfy state machine transitions. Thetransition number and associated condition(s) are shown in FIG. 7. Theconditions for satisfying one or more of the states may differ dependingon whether the EHF communication unit is a transmitter or a receiver.The table of FIG. 7 reflects these differences and does so by prefacingtransmitter specific conditions with a “Tx:” and prefacing receiverspecific conditions with a “Rx:”. If no Tx or Rx preface is used, thenthe condition applies to transmitter and receiver units. FIG. 8 is agraphical illustration showing state transitions of each EHFcommunication unit arranged in a wake up loop as shown in FIG. 9,including signals applied to the CP5 and CP6 pins of those communicationunits. It is understood that the progression of consciousness (POC)state machine can be implemented in any communication unit, regardlessof which transport mode it supports or which wake up loop configurationis used. The wake up loop configuration of FIG. 9 being used is beingreferenced in connection to the POC state machine discussion, but it isunderstood that the POC state machine may be used in the wake up loopconfigurations of FIGS. 10 and 11.

The POC state machine is operative to handle both the pin-strapped andserial interface control modes of any EHF communication unit. Asdiscussed above, the mode of operation can be set by the states ofvarious control (or configuration) pins, such as, for example, CP1 pin308, CP2 pin 309, CP3 pin 310, and CP4 pin 311. When an EHFcommunication unit is configured for a pin strap mode of operation, oneor more of the control pins may specify which transport mode the unitshould operate in according to when a communications link isestablished. The POC state machine may manage the unit's progression ofconsciousness as it “wakes up” to establish a communications link. Aswill be explained below, the POC state machine “wakes up” the unit bytransitioning from state to state until it reaches a data transportstate. The transition from one state to another may depend on thesatisfaction of one or more conditions, and the notification of a statechange or satisfaction of a condition may be transmitted in a loop likemanner around the wake-up loop. Some of the conditions for executingstate change transitions may vary depending on which transport mode isselected.

The notification of condition satisfaction is made during the wake-uploop and communicated among the EHF communication units. As the closedlooped link is established, each unit in the link progressively “wakesup” and transitions to new states in a loop-like manner. This loop-likesequence of state changes is referred to herein as a progression ofconsciousness. Thus, in a progression of consciousness link awaking, astate change of an EHF communication unit may depend on a state changeof an upstream EHF communication unit. In particular, the upstream EHFcommunication unit may be the immediately preceding EHF communicationunit in the closed loop. Some of the conditions for executing statechange transitions may vary depending on which transport mode isselected. For example, when a first EHF communication unit transitionsfrom one state to another, it may transmit a signal to a downstream EHFcommunication unit. This transmitted signal may affect a future state ofthe first EHF communication unit. That is, the transmitted signal mayinduce a state change in one or more downstream EHF units in the wake-uploop, which results in a future state change from the first EHFcommunication unit.

FIG. 9 shows an illustrative full duplex link of units showingcontactless EHF couplings and CP5 connections according to anembodiment. As shown, first device 910 includes receiver unit 912 andtransmitter unit 914, and second device 920 includes transmitter unit922 and receiver unit 924. Units 912, 914, 922, and 924 may have thesame pin configuration and functional blocks as unit 300 of FIG. 3.Receiver unit 912 may be operative to receive contactless EHF signalsfrom transmitter unit 922, and transmitter unit 914 may be operative totransmit contactless EHF signals to receiver unit 924. Thus, receiverunit 912 and transmitter unit 922 may form a first contactlessly coupledpair, and receiver unit 924 and transmitter unit 914 may form a secondcontactlessly coupled pair. In addition, receiver unit 912 maycommunicate with transmitter unit 914 via wired path 913, and receiverunit 924 may communicate with transmitter unit 922 via wired path 923.Wired path 913 (also labeled as CP5₁) may be coupled to respective CP5pins of both units 912 and 914, and wired path 923 (also labeled asCP5₂) may be coupled to respective CP5 pins of both units 922 and 924.Thus, communication between first device 910 and second device 920 canbe achieved via the first and second contactlessly coupled pairs andcommunication among units within any device can be achieved via wiredpathways (e.g., pathways connected to CP5 pins). FIG. 9 also shows thatthe CP6 pin 915 (labeled as CP6₁) for transmitter 914 is being driven bycircuitry other than receiver unit 912 (e.g., such as a host system),and that the CP6 pin 925 (labeled as CP6₂) for transmitter unit 922 isbeing driven by receiver unit 924.

A wake up loop of FIG. 9 may begin with transmitter unit 914, andproceed to receiver unit 924 via contactless EHF signals being emittedby transmitter unit 914. The loop continues from receiver unit 924 totransmitter unit 922 via wired path 923 and/or wired path 925. Fromtransmitter unit 922, the loop continues to receiver unit 912 viacontactless EHF signals being emitted by transmitter unit 922. The loopis completed via wired path 913, which couples receiver unit 912 totransmitter unit 914. Thus, in one embodiment, the closed loop link ofFIG. 9 is a clockwise loop starting with transmitter unit 914 and endingwith receiver unit 912. Thus, in this embodiment, receiver unit 924 isimmediately downstream of transmitter unit 914, and transmitter unit 914is immediately upstream of receiver unit 924. In another embodiment, theclosed loop link can start with transmitter unit 922 and end withreceiver unit 924 in a clockwise loop that includes receiver unit 912and transmitter unit 914. In this embodiment, transmitter unit 922 maybe the first EHF unit to be activated in the link, in which case theCP6₂ pin may be activated by the host system of device 920. In yetanother embodiment, the closed loop link can move in a counter-clockwisedirection. In such an embodiment, devices 910 and 920 would betransposed (e.g., device 910 would be placed left of device 920).

POC state machine 600 can include the following states: OFF state 602,power ON reset state 604, CP4 check state 606, attentive state 608,beacon/listen state 610, link training state 612, capabilities messagingstate 614, hold state 616, data transport state 618, and data transportidle state 620. Actions taken by POC state machine 600 in response totransitioning to each state may vary depending on whether the unitexecuting the POC state machine is functioning as a transmitter unit ora receiver unit.

POC state machine 600 includes a beaconing/listening state machine thatcycles among states 604, 606, 608, and 610 until conditions satisfy atransition to link training state 612. The beaconing/listening statemachine may be referred to generally as a “link discovery” statemachine. These states (e.g., states 604, 606, 608, and 610) may also bereferred to herein as initial states or initialization states. Linkdiscovery may be implemented by having a transmitter device transmit abeacon signal, periodically, for a short duration of time, instead ofbeing enabled continuously. Similarly, a receiver unit may be enabled tolisten for the beacon, for a short duration of time, instead of beingenabled continuously. A ratio of the transmit and receive durations oftime can be established to ensure periodic overlap (i.e., that thereceiver will be activated to detect the beacon within a reasonablenumber of periods). If a transmitter beacon is within an appropriaterange to establish a link, the transmitter's beacon will be picked up byan active receiver. This periodic beaconing and listening approachallows for conservation of power (and extended battery life).

State machine 600 may begin in OFF state 602 and may exist in this statewhen no power is applied to the unit's V_(DD) pin. An EHF communicationunit can transition from OFF state 602 to power ON reset state 604 whenpower (e.g., V_(DD)) is applied to the unit's V_(DD) pin. For example,transmitter unit 914 may transition to power ON reset state 604 when anexternal power source is applied to V_(DD) pin 301. As its name implies,power ON reset state 604 includes powering ON of the unit and a reset ofthe unit. As the unit receives power via its V_(DD) pin, its internalV_(DD) pin may also receive power. When a power level on the internalV_(DD) pin reaches or exceeds a threshold (e.g., 80% of full supplylevel), the unit may be reset. The POC state machine transitions toTRBS-Check state 606 when the internal V_(DD) exceeds the threshold.During reset, one or more or all of the unit's outputs may be tri-stated(not driven or floating). Example output pins may include high-speedinput/output pins 302/303, low-speed input/output pins 304/305, CP5 312,CP6 313, and CP1 308.

In TRBS-Check state 606, the unit checks whether its CP4 pin (e.g., CP4pin 311) is HIGH, LOW, or FLOATING. As discussed above, the status ofthe CP4 pin can dictate whether the unit will operate as a transmitteror a receiver, or whether the unit is to undergo testing in a serialinterface control mode. If the CP4 pin is HIGH or LOW, the POC statemachine transitions to attention state 608, as indicated by transition3. If the device is configured to go directly to Data Transport state618 (bypassing states 608, 612, 614, and 616), the POC state machine maygo directly to Data Transport state 618 from TRBS-Check state followingarrow 19 after the determination of the state of the CP4 pin. After theCP4 pin determination is made, the POC state machine may delaytransition to state 608 by a first period of time if the CP4 pinspecifies the unit should operate as a transmitter, and by a secondperiod of time if the CP4 pin specifies the unit should operate as areceiver. The second time period may be greater than the first timeperiod. These transition delays may assist in link discovery. If the CP4pin is FLOATING, the POC state machine may undergo transition 6.

In attentive state 608, the unit may activate circuitry other than thatnecessary to operate the beacon/listen state machine to evaluate whetherto advance its state of consciousness (in which case it proceeds to linktraining state 612) or function in the link discovery cycle (in whichcase, state machine 600 proceeds to beacon/listen state 610). Theconditions for determining whether POC state machine 600 proceeds tostate 610 via transition 4 or state 612 via transition 9 differdepending on whether the unit is a receiver or a transmitter.

Receiver unit conditions for both transitions are now discussed. Thereceiver unit may monitor for the presence of a beacon signal beingemitted by a transmitter within an attentive state time period, which iscontrolled by Beacon/Listen module 390 of FIG. 3. If a beacon signal isdetected within the attentive state time period, then the POC statemachine may transition to link training state 612, via transition 9.Detection of any EHF signal, which may need to be larger than a minimummagnitude threshold, by the receiver unit may qualify as a valid beaconsignal since the receiver unit has not yet been trained. Such trainingmay be performed when the POC state machine advances to link trainingstate 612. Also in response to detecting a beacon signal within theattentive state time period, the receiver unit may pulse its CP5 pin(used in output mode) and set its CP6 pin (used in output mode) to HIGH.For example, receiver unit 924 may monitor for the presence of a beaconsignal being emitted by transmitter unit 914. This is shown in FIG. 8,where in response to detecting the beacon signal from transmitter unit914, receiver unit 924 pulses its CP5 pin 923 at time, t₁, and then setsits CP6 pin 925 to HIGH at time, t₂.

If no beacon signal is detected within a Wake-Up time period, which isset by module 390, then the POC state machine advances to beacon/listenstate 610, via transition 4. Once the POC state machine is in listenstate 610, various circuitry other than that needed to run beacon/listenstate machine may be powered OFF and may remain powered OFF until aWake-Up pulse is asserted by beacon/listen module 390. The Wake-Up pulsemay cause the POC state machine to undergo transition 5, whichtransitions from state 610 to power ON reset state 604. In addition, theWake-Up pulse restarts the Wake-Up time period, during which the POCstate machine progresses through power ON reset state 604, TRBS-Checkstate 606, and attentive state 608, before returning to listen state610, or proceeding to link training state 612 if a beacon signal isdetected.

Transmitter unit conditions for transitions 9 and 4 are now discussed.The transmitter unit may monitor status of its CP5 and CP6 pins todetermine how to make a state change transition when in attentive state608. The POC state machine may transition to link training state 612(via transition 9) when its CP6 pin is HIGH and the CP5 pin pulseswithin a time period. For example, transmitter 914 may transition tolink training state 612 in response to a pulse on CP5₁ pin 913 when CP6₁915 is HIGH. This can be seen in FIG. 8 where transmitter unit 914transitions to link training state 612 at time, t₃, (shown as “sendtraining” in FIG. 8) in response to a pulse on CP5₁ 913 when CP6₁ 915 isHIGH. Similarly, transmitter 922 may transition to link training state612 when CP5₂ pin 923 pulses when CP6₂ 925 is HIGH at time, t₄.

POC state machine 600 may transition to beacon state 610 (via transition4) when the CP6 pin is LOW or if there is no CP5 pin pulses within atime period while CP6 pin is HIGH. Once the POC state machine is inbeacon state 610, it may remain in this state until there is an CP5pulse and its CP6 pin is HIGH. Consequently, the occurrence of an CP5pulse while CP6 is HIGH may also cause the POC state machine to quicklystep through states 604, 606, and 608 to arrive at link training state612. While a transmitter unit is in Beacon/Listen state 610 and CP6 isHIGH, it will periodically wake up additional circuitry in thetransmitter unit and send a maximum powered EHF pulse for a firstpre-determined time period. Once this time-period has elapsed, thetransmitter unit will disable the additional circuitry and will wait fora second pre-determined time period until repeating the EHF pulse.

In link training state 612, transmitter unit 914 initiates training bytransmitting a training pattern to receiver unit 924 to identify theoptimum settings for one or both of the transmitter and receiver units.The training pattern may include an alternating High and Low sequence ofbits or symbols (or High and Idle symbol or a combination thereof) of apre-defined frequency, synchronization symbol(s), and/or a clockpattern, repeated for a certain predetermined period of time or untiltransmitter unit 914 receives an acknowledgement of training completionfrom receiver unit 912. The training pattern may also include a fixedsequence of bits or symbols to aid the receiver in calibrating itsparameters. The symbols may be multi-level signals or two level signals.The symbols may also refer to multi-level signals that are transmittedin quadrature (In-phase and Quadrature phase input signals that aretransmitted using Quadrature modulation techniques, e.g. QAM, QPSK). Asshown in FIG. 8, the acknowledgement loop begins with the receiver unit924 completing the training of its parameters and subsequently assertingthe CP5₂ pin 923 while keeping CP6₂ pin 925 HIGH, at time, t₄. Thisevent triggers the transmitter unit 922 to initiate transmission of thetraining pattern to the receiving unit 912. After the receiving unit 912completes training of its parameters it asserts CP5₁ pin 913, at time,t₅. This event serves as an acknowledgement of the completion of thelink-training phase. Referring to FIG. 8, transmitter unit 914transitions to state 614 at time, t₅, and transmitter unit 922transitions to state 614 at time, t₆.

During link training, the transmitters may optimize the accuracy of theamplitude of the transmitted carrier. For example, the transmittedcarrier amplitude may be calibrated to one of several references so thatthe transmitted power or amplitude remains in a targeted range. Thereference could be a stable signal parameter in the transmitter unit.For example, a reference voltage derived from a bandgap could serve asan ideal reference. In one example, the EHF signal mapping may use afull carrier (e.g., 100% of predetermined or programmed carrieramplitude) for a logic 1, a partial carrier (fraction of a predeterminedor programmed carrier amplitude) for a logic 0, and no carrier for anIdle state. The size of the partial carrier may be programmable to anyone of several different thresholds (e.g., 25%, 37.5%, 50%, or otherpercentage of a predetermined or programmed carrier amplitude). Thecarrier amplitude in one or more of these states may need to becalibrated based on the reference to generate carrier amplitudes thatare optimized for accuracy. This may enable the transmitter to transmitmultiple amplitude carrier signals thereby increasing bandwidthefficiency and/or enabling the receiver to detect the transmittedsymbols with greater reliability.

During link training, the receiving units may calibrate one or more ofits parameters to optimize the performance of the contactless link whilereliably recovering the logic symbols, possibly with a certain errorcriteria. In an example, similar to the one provided above for thetransmitter unit, the receiver unit may need to detect symbols from anEHF signal that may be of different carrier amplitudes—logic 1 symbolmay refer to a full carrier amplitude, logic 0 for a partial carrieramplitude and Idle symbol for no carrier. The receiver may not haveaccurate information to be able to detect these symbols reliably.Therefore, it may have to perform a calibration sequence to be able todetect these symbols with sufficient margin.

Calibration may be performed by executing one or more of the followingapproaches. For example, in one approach, the reference levels fordetecting the levels of the demodulated signal (or baseband signal) maybe calibrated to provide maximum margin for symbol detection. In anotherapproach, the amplitude of the signal envelope can be tracked and thegain of the signal path can be calibrated to meet a signal amplitudetarget. In yet another approach, if slicers use clocks for sampling ofdata, then clock phase adjustment calibration can be performed tooptimize the sampling point of baseband symbols. Additional calibrationapproaches may include transmission of a clock pattern (possibly from ahost system or generated on die of the one or more communication units)that may be used by the receiver units to compare the clock frequenciesand calibrate the phase or clock frequency of the frequency generator;synchronization symbols may be used to identify frame or packetboundaries.

Additional parameters may be calibrated in the transmitter and/orreceiver during link training without limiting the scope of theinvention. A transmitter unit can send “link training” information toits counterpart receiver unit. The link training information may be aspecific data pattern that enables the counterpart receiver unit tooptimize itself for receiving data from the transmitter unit. In effect,the receiver unit uses the received link training information tocalibrate itself to the transmitter unit so that it can accurately mapincoming EHF signals to a logic 1 state, logic 0 state, or Idle state.Link training state 612 may involve calibrating the sensitivity of thereceiver units to be able to detect the EHF signal reliably, forexample, by meeting bit-error rate criteria. This may involvecalibration of various parameters in the RF analog front-end which mayinclude the LNA gain, slicer reference levels or slicer sensitivity,sensitivity of the squelch detector, and clock phase adjustment.

In capabilities message state 614, a transmitter unit sends acapabilities message to its counterpart receiver unit. The transmitterunit may send this message repeatedly until its CP5 pin is pulsed oruntil a timer times out. The message may specify information such as thetransport mode, ID codes, etc. The receiver unit will monitor thereceived contactless signals for the capabilities message, and when themessage is received, it may validate it against one or more validatingparameters (e.g., transport mode, key information such as vendor IDs,and readiness state). If the message is validated, the receiver unit maypulse its CP5 pin. If no validated message is received within a timelimit, then the receiver unit may revert back to state 610. Thecapability message may include information regarding the transport modeprotocol.

The capabilities message may be communicated using any one of severaldifferent approaches. For example, in one approach, the capabilitiesmessage sent by the transmitter unit may embody a series ofpulse-width-coded (PWC) symbols. Additional details regarding use of PWCsymbols to communicate the capabilities message is discussed below inconnection with the description accompanying FIGS. 16-21. In anotherapproaches, the capabilities message may be communicated using packettransfers. The capability messaging may be performed in terms of packettransfers that are of a predetermined format. A single messaging packetmay include a packet header and a packet body. The packet header mayinclude one or more synchronization symbols, packet type information,vendor ID information, length of packet information while the body ofthe packet may include information regarding the transport modeprotocol, error checking codes, data patterns that may aid the receiverin optimizing settings and other information that may be relevant toimproving the capabilities of the EHF link. The messaging may beperformed using multiple packets that may or may not be of the sametype. In this case, the packet header may include information regardingthe contents of a particular packet.

A receiver unit may perform transition 11 (i.e., transition fromcapabilities message state 614 to hold OFF state 616) when the receiverdetermines that it has validated a message received from a transmitterunit. For example, receiver unit 924 may transition to the hold OFFstate at time, t₆, and receiver unit 912 may transition to hold OFF attime, t₇.

Hold OFF state 616 is operative as a transition delay mechanism indelaying execution of transition 12. Hold OFF state 616 may be includedas part of POC state machine 600 to prevent the capabilities messagefrom being erroneously processed by a receiver unit. In particular, itmay prevent the receiver unit from transmitting the capabilities messageas its output. For receiver units, hold OFF state 616 may delaytransition 12 by a third time period, and for transmitter units, holdOFF state 616 may delay transition 12 by a fourth time period. Thefourth time period may be relatively negligible compared to the thirdtime period. For example, in one embodiment, transmitter units may spendone clock cycle at state 616, whereas receiver units may wait multipleclocks at state 616. This disparity in hold time may provide sufficienttime for the for state changes to propagate around the wake up loop,thereby enabling the receiver units to ignore the capabilities messagebeing transmitted by their counterpart transmitter units until thetransmitter units transition to a data transport state. This isillustrated in FIG. 9 where, for example, transmitter unit 914 istransmitting its capabilities message while its counterpart receiverunit 924 is in its hold OFF state. Although receiver unit 924 could havetransitioned to data transport state at time, t₆, that transition isdelayed by hold OFF state 616 to enable transmitter unit 914 totransition to the data transport state at time, t₈.

Data transport state 618 may represent the state in which thecommunication unit is ready to transmit and/or receive data according toa transport mode. As discussed above, the transport mode may be based onthe states of CP1 pin 308, CP2 pin 309, CP3 pin 310, and CP4 pin 311. Insome embodiments, when a receiver unit enters into state 618, it maydrive its CP5 pin HIGH. This is shown in FIG. 8, for example. In otherembodiments, for example, when the transport mode is USB 2.0, the CP5wired path may be used for interchip communication and thus may not bedriven HIGH.

POC state machine 600 may transition to data transport idle state 620when conditions of transition 13 are satisfied. Data transport idlestate 620 may enable the communications unit to enter into a quickentry/exit low power state for one or more transport modes. A receiverunit may enter into state 620 after it does not detect any EHF signalingactivity (i.e., its counterpart transmitter unit does not transmit anydata) after a fifth period of time. A transmitter unit may enter intostate 620 after it does not detect any activity on its baseband inputs(e.g., pins 302-305) after a sixth period of time. In some embodiments,the fifth and sixth periods of time may be the same.

During data transport idle state 620, both the receiver and transmitterunit may power cycle various components OFF to save power, but turnthose component ON to check whether the unit needs to exit idle state620 and return to state 618 or another state. For example, a transmitterunit may power cycle its transceiver, but may supply power to its inputbuffer to detect input signals. The transmitter may power cycle itstransceiver to transmit a “keep alive pulse” to its counterpart receiverunit so that the receiver unit knows not to transition away from state620. The “keep alive pulse” may be a series of “1's” every clock cyclefor a fixed period of time. The receiver unit may power cycle itstransceiver so that it can detect the “keep alive pulse.”

POC state machine 600 may transition to data transport state 618 fromdata transport idle state 620 when the conditions of transition 14 aresatisfied. A transmitter unit may transition to state 618 when itreceives a signal on its input buffer. A receiver unit may transition tostate 618 when it receives a non-Idle signal from its counterparttransmitter. A non-Idle may be a signal other than the keep alive pulse.Upon receipt of an EHF signal from the transmitter unit, the receiverunit may be inhibited from powering down until the EHF signal isclassified as a keep-alive or wake-up signal.

Transitions 9-14, discussed above, referred to state change transitionthat result in progression of consciousness advancements of the POCstate machine. Transitions 15-18, which are now being discussed, referto state change transitions that restart the progression ofconsciousness. That is, if any of transitions 15-18 are implemented byPOC state machine 600, POC state machine 600 may re-enter into abeacon/listen state machine at state 610. In transition 15, a receiverunit may advance to state 610 if insufficient training signals have notbeen received within a period of time. In other words, transition 15 mayoccur if the link training times out. In transition 15, a transmitterunit may advance to state 610 if its CP5 pin is not pulsed within a timeperiod or if its CP6 pin goes LOW.

In transition 16, a receiver unit may change from state 614 to state 610if a valid message is not received within a time period or it CP6 pingoes LOW, and a transmitter unit may change from state 614 to state 610if its CP5 pin is not pulsed within a time period or if its CP6 pin goesLOW. In transition 17, a transmitter unit may change from state 618 tostate 610 if CP6 goes LOW, and a receiver unit may change from state 618to state 610 for different conditions including but not limited tokeep-alive or wake-up signal is not received, if the connection isbroken due to a weak EHF signal, the data transport traffic is idle fora period of time. In transition 18, a receiver unit may change fromstate 620 to state 610 if no EHF signal activity occurs within a seventhperiod of time. In some embodiments, the seventh period of time may begreater than the fifth period of time. A transmitter unit, in transition18, may change from state 620 to state 610 if its CP6 pin goes LOW or ifits CP5 pin goes LOW for an eighth time period.

Transition 19 refers to a state change in which a generic low speed datatransport mode of operation is needed that bypasses the progression ofconsciousness. The POC state machine may undergo transition 19 based onthe specific register settings of logic and control circuitry 370 at themoment of the transition. These register settings may have been updatedduring the serial interface control mode state 622 or during thepin-strapped control mode. Transition 19 may occur when amicrocontroller is connected to the CP6 pin and one of the low speeddata pins (e.g., pins 304 or 305). In this transition, the EHFcommunication unit may be used as a stand-alone link that is managed bya microcontroller.

Transitions 6-8 and 20 refer to state changes associated with the serialinterface control mode according to various embodiments. In oneembodiment, if the CP4 pin is FLOATING at CP4 Check state 606, the POCstate machine may transition to serial interface control mode 622 viatransition 6. Once in the serial interface control mode 622, thepin-strapped mode is locked out and the communications unit isconfigured to inhibit an auto-sleep or low power mode by setting a “stayawake bit” HIGH. The “stay awake bit” is an internal bit in logic andcontrol circuitry 370 that is updated by the serial interface control,thereby not requiring a dedicated pin for controlling this bit. Forexample, through an SPI pin interface several on-chip register bits canbe updated or read which may include the “stay awake bit”. Once the“stay awake bit” is HIGH and the CP4 pin goes LOW or HIGH, the POC statemachine transitions to data transport state 618 via transition 8,thereby bypassing states 608, 612, 614, and 616. If, while in serialinterface control mode state 622, the power is removed, the POC statemachine may transition to OFF state 602 via transition 7.

If, at any point, the state of the CP4 pin goes to FLOATING while thePOC state machine in is in any one of states 608, 612, 614, 618, or 620,the POC state machine may transition to interface mode state 622. It isunderstood that the various states and arrangement of POC state machine600 are merely illustrative and that additional states may be added andsome states may be omitted.

It is further understood that although POC state machine 600 isimplemented by one particular EHF communication unit, that state machine600 may depend on similar state machines being implemented in other EHFcommunication units to advance through its states to arrive at the datatransport state. Thus, regardless of how many EHF communication unitsare being used to establish one or more EHF communication links, theinterdependency of the state machines may result in a syncing of statemachines. Thus, so long as all of the state machines remain in sync,each state machine may progress its consciousness. However, if one ofthe state machines falls out of sync, this may cause all of the statemachines to fall out sync, thereby resulting in a restart of the wake uplink progression. For example, if one of the state machines fails toadvance to a next state, and transitions back to beacon/listen state610, all of the other state machines may also transition back tobeacon/listen state 610. Transitioning back to state 610 can effectivelyreset each of the state machines, thereby restarting the process ofestablishing one or more EHF communication links and preventing falseprogressions in state change advances.

FIG. 10 shows another illustrative full duplex closed loop link of unitsshowing contactless EHF couplings and CP5 connections according to anembodiment. The link arrangement of FIG. 10 is similar to that of FIG.9, but is setup for a USB On-the-Go (OTG) configuration. As shown, firstdevice 1030 includes receiver unit 1032 and transmitter unit 1034, andsecond device 1040 includes transmitter unit 1042 and receiver unit1044. Receiver unit 1032 may be operative to receive contactless EHFsignals from transmitter unit 1042, and transmitter unit 1034 may beoperative to transmit contactless EHF signals to receiver unit 1044. CP5communications paths 1033 and 1043 may exist between respective EHFcommunication units as shown. In addition, the CP1 pins of units 1032and 1034 may be connected together via wired pathway 1035 that includesa resistor or other impedance element, and the CP1 pins of units 1042and 1044 may be connected together via wired pathway 1045 that includesa resistor or other impedance element. The CP6 pins of units 1032 and1034 may be connected together via wired pathway 1037 that includes aresistor or other impedance element, and the CP6 pins of units 1042 and1044 may be connected together via pathway 1047 that includes a resistoror other impedance element.

In the OTG configuration, devices 1030 and 1040 may need to determinewhich device will be the host and which will be the client. This may beaccomplished by having one or both devices assert a signal on the CP1pins. In some configurations, CP1 may be set HIGH, indicating that it isa USB device. In other configurations, CP1 may be set LOW, indicatingthat it is a USB host. In still yet other configurations, CP1 may befloated, indicating that it is a USB OTG device. As shown, pathways 1035and 1045 may be coupled to respective controllers (not shown) that mayeach assert (or not assert) that signal. Depending on the capabilitiesmessage exchange, the CP1 pin of an USB OTG device may be pulled LOW bythe receiver unit, indicating that it is a USB host or the CP1 pin maybe pulled HIGH by the receiver unit, indicating that it is a USB device.If a capabilities message indicates that both devices are configured asa USB host or as a USB device, the POC state machine will exit to theBeacon/Listen state via transition 16. If a capabilities messageindicates that a USB OTG device is connected to a USB host, the CP1 ofthe receiving device will be pulled HIGH indicating that it should beconfigured as a USB device. If a capabilities message indicates that aUSB OTG device is connected to a USB device, the CP1 of the receivingdevice will be pulled LOW indicating that it should be configured as aUSB host. As also shown, pathways 1035 and 1045 may be coupled to theirrespective devices.

When devices 1030 and 1040 attempt to form a link, one device may assertthe CP6 pin on its transmitter unit and the other device may leave theCP6 pin floating. As shown, pathways 1037 and 1047 are coupled torespective controllers (not shown). In one embodiment, a controllerassociated with device 1030 may drive the CP6 pin HIGH on transmitterunit 1034 to initiate a link, and a controller associated with device1040 may leave the CP6 pin floating on transmitter unit 1042. In thisembodiment, the CP6 pin may be driven by receiver unit 1044. Thus, inthis embodiment, the wake up loop can start at transmitter unit 1034 andmove clockwise to receiver unit 1044, transmitter unit 1042, andcontinue at receiver unit 1032. In the same manner, a wake up loop canstart in FIG. 9 at transmitter unit 914 and move clockwise to receiverunit 924, transmitter unit 922, and continue at receiver unit 912.

The wake up loops of FIGS. 9 and 10 are both single lane full duplexlinks. If desired, multiple lane links can be achieved by using multipleinstances of the single lane full duplex links of FIG. 9 or FIG. 10. Forexample, a two lane link can be achieved by using two instances of thefull duplex links of FIG. 9. FIG. 11 shows an illustrative multi-lanelink according to an embodiment. In some embodiments, the link of FIG.11 may be a multi-lane DisplayPort link. As shown, device 1150 caninclude receivers units 1152, 1154, 1156, and 1158, and transmitter unit1159, and device 1160 can include transmitter units 1162, 1164, 1166,and 1168, and receiver unit 1169. In device 1160, CP5 and CP6 pins ofreceiver unit 1169 are fanned out to each of transmitter units 1162,1164, 1166, and 1168. In device 1150, the CP5 pins of receiver unit 1158and transmitter unit 1159 are coupled together, and the CP6 pin oftransmitter unit can be driven by a controller (not shown). The wake uploop of FIG. 11 may start with transmitter unit 1159, and proceedclockwise to receiver unit 1169, and then the loop proceeds to each oftransmitter units 1162, 1164, 1166, and 1168 substantiallysimultaneously, followed by and ending substantially simultaneously withreceivers units 1152, 1154, 1156, and 1158. Receiver unit 1158 may bethe sole unit that communicates with transmitter unit 1159 via the CP5pins. For simplicity, only a few of the interconnected signals are shownto prevent overcrowding of FIG. 11.

Reference is now made to FIGS. 12-15 to discuss various implementationsof the beacon/listen cycle of a POC state machine. In particular, thefollowing discussion describes in more detail how circuitry within anEHF communication unit is used to implement the beacon/listen cycle(e.g., state 610 of FIG. 6). FIG. 12 shows an illustrative schematicshowing circuitry of unit 1200 that may be used in executing thebeacon/listen cycle according to an embodiment. FIGS. 13A-13D showillustrative beaconing and listening timing diagrams, each operatingaccording to different clocking speeds, according to variousembodiments. FIG. 14 shows an illustrative flowchart of steps that canbe performed by a transmitter unit that is beaconing according to anembodiment. FIG. 15 shows an illustrative flowchart of steps that can beperformed by a receiver unit that is listening for a beacon signalaccording to an embodiment.

FIG. 12 is shown to include register 1210, oscillator 1220,beacon/listen timer 1230, beacon/listen circuitry 1240, register 1250,stay awake timer 1260, control/configuration pins 1270, 1272, and 1274.Register 1210 can be programmed with data that can be loaded intooscillator 1220, for example, during the attentive state (e.g.,attentive state 608). Oscillator 1220 can operate according to any oneof several different frequencies based on the data received fromregister 1210. For example, oscillator 1220 may select one offrequencies 1222, 1224, or 1226 to drive beacon/listen timer 1230. Theselected frequency may control the clocking speed of timer 1230. It willbe appreciated that increases in clocking speed frequency can result infaster operation, along with increased power consumption, and thatdecreases in clocking speed frequency can result in slower operation,but with decreased power consumption. The selection of a frequency maydepend on the end use application of unit 1200. It will be furtherappreciated that oscillator 1220 can be part of or included within timer1230. The beacon/listen timers for a set of EHF communication devicesmay be pre-programmed or may be set by the system prior to entering thebeacon/listen mode.

Beacon/listen timer 1230 may provide a power ON beacon pulse or a powerON listen pulse, depending on whether unit 1200 is configured to operateas a transmitter or a receiver. The duration of the beacon pulse or thelisten pulse determines the duration in which the device 1200 operatesas a transmitter or a receiver, respectively. If unit 1200 is configuredto operate as a transmitter, timer 1230 may provide the power ON beaconpulse, and if operating as a receiver, timer 1230 may provide the powerON listen pulse. For example, unit 1200 may be configured based on thestate of configuration pin 1274. In some embodiments, the state on pin1274 may be used to select an appropriate output of selector 1232.

The beacon/listen timer may generate a power ON beacon pulse of a fixedtime duration (e.g., 20 ns) during which various circuitry is activatedto transmit an EHF beacon signal every fixed number of clock cycles(e.g., 100 clock cycles). The power ON beacon pulse may cause beacononly circuitry 1244 to be powered ON. Beacon only circuitry 1244 mayonly include the circuitry components necessary to transmit an EHFbeacon signal. This may include, for example, EHF transmitter 322 ofFIG. 3. This fixed time duration of the beacon pulse can be the sametime duration regardless of the frequency set by oscillator 1220. Forexample, in one specific embodiment, the fixed time duration can beabout 20 ns, and the fixed number of clock cycles can be 100. Timingdiagrams showing the power ON beacon pulse according to the parametersof this specific embodiment are shown in FIGS. 13A-13D. In particular,the beacon pulses are shown in the Tx Cycle.

The power ON listen pulse may set a fixed time duration during whichvarious circuitry is activated to listen for an EHF beacon signal. Insome embodiments, the entire EHF communication unit may be activated tomonitor for the presence of an EHF beacon signal. The beacon/listentimer may generate a power ON listen pulse for a first number of clockcycles (e.g., 200 clock cycles) out of every second number of clockcycles (e.g., 1,000,000 clock cycles). The second number of clock cyclesmay be orders of magnitude greater than the first number of clock cyclesto minimize power consumption. Timing diagrams showing the power ONlisten pulse according to the parameters of this specific embodiment areshown in FIGS. 13A-13D. In particular, the listen pulses are shown pulsein the Rx cycle.

A timing relationship can exist between the beacon and listen pulses topromote beacon detection between coupled EHF communication devices. Forexample, the beacon pulse may be asserted at least once during everylistening pulse. In other examples, the beacon pulse may be asserted atleast twice during every listening pulse. This may be accomplished bysetting the fixed number of clock cycles of the beacon pulse to be afraction of the first number of clock cycles of the listening pulse.Referencing the illustrative numbers discussed above, the fixed numberis 100 clock cycles and the first number is 200 clock cycles. Thus, thefixed number is one-half of the first number, thereby ensuring that atleast two 20 ns beacon pulses will occur every listening pulse. It maybe desirable for the beacon pulse to be asserted at least twice duringevery listening pulse to account for potential variations in clockingspeeds of the clocks operating in the transmitting and receiving units.For example, if only one beacon pulse is transmitted for each listenpulse, and the clocks in both units are not operating in sync with eachother, there is a potential for the beacon pulse to be transmittedoutside of the listen pulse. However, by increasing the frequency inwhich beacon pulses are transmitted, the can ensure that at least onebeacon pulse will be transmitted during the listen pulse, even if theclocks in both units are operating at slightly different speeds (e.g.,within 20% of each other).

The timing relationship of the beacon pulse and the listen pulse can bereversed such that the transmitter unit has a relatively long beaconpulse and the receiver unit has a relatively short listen pulse. Inother words, the receiver and transmitter cycles can be transposed toachieve the same result. This is illustrated in FIG. 13D.

FIG. 13A, for example, shows the timing diagram of the power ON beaconpulse and the power ON listen pulse when the beacon/listen timer is setto operate at a clock speed of F₁ Hz. F₁ Hz is set to 1 MHz in thisexample. The timing diagram of FIG. 13A may adhere to theabove-described example in which the power ON beacon pulse can be set tohave a fixed time duration pulse length of 20 ns every 100 clock cycles.The period of the beacon ON pulse can be about 100 μs. The power ONlistening pulse of FIG. 13A can have a period of about 1000 ms and aconstant listen duration of about 200 μs. As shown, at least two beaconpulses exist within the constant listen duration.

FIG. 13B, for example, shows timing diagrams of the power ON beaconpulse and the power ON listen pulse when the beacon/listen timer is setto operate at a clock speed of F₁ Hz. F₁ Hz is set to 1 MHz in thisexample. As shown, the period and constant listen duration of thelistening pulse can be same as that in FIG. 13A, but the period of thebeacon ON pulse be same as the constant listen period. Thus, FIG. 13Bshows an example where only one beacon pulse can be detected during thelisten pulse.

FIG. 13C, for example, shows timing diagrams of the Rx and Tx cyclesoperating at a clock speed of F₂ Hz, and wherein the Rx/Tx relationshipis set such at least three beacon pulses can be transmitted during thelisten pulse. As shown, the listen pulse can have a period,Listen_(period), and a constant listen duration. The period of thebeacon ON pulse can be a fraction of the constant listen duration, shownhere to be ⅓^(rd) (e.g., ⅓*Constant_Listen) of the constant listenduration. Thus, in this timing diagram example, three beacon pulses mayexist for every listen pulse.

FIG. 13D, for example, show timing diagrams of the Rx and Tx cyclesoperating at a clock speed of F₃ Hz. FIG. 13D illustrates alternativeroles of the Rx and Tx cycles, at least compared to the roles thosecycles perform in FIGS. 13A-13C. As shown, the Tx cycle may provide abeacon pulse having a constant beacon duration (shown as ConstantBeacon) every beacon period (shown as Beacon Period). The Rx cycle mayhave listen pulse that pulses at a fraction of the constant beaconduration. For example, as shown, the fraction may be one-half such thatthe listen pulse of a fixed duration (e.g., 20 ns) is provided every½*Constant_Beacon. This ratio is illustrative, but may ensure that thereceiver unit listens for a beacon pulse while the transmitter unit isproviding its beacon pulse.

Reference is now made to FIG. 14. Starting at step 1402, thebeacon/listen tinier may be activated. The beacon/listen timer may beactivated when the POC state machine enters into the beacon/listen state(e.g., state 610). At step 1404, the beacon/listen tinier can provide apower ON beacon pulse once a period to periodically wake up thecircuitry that transmits an EHF beaconing signal, the pulse having afixed time duration. For example, beacon only circuitry 1244 may beperiodically woken up. At step 1406, the circuitry that transmits an EHFbeaconing signal may be woken up in response to power ON beacon pulsesreceived from the beacon/listen timer. The power ON beacon pulse may,for example, be any one of the beacon pulses shown in FIGS. 13A-13D. Asshown, any one of these beacon pulses has a fixed time duration duringwhich the pulse is HIGH. At step 1408, an EHF beacon signal may betransmitted for a fixed time duration of the power ON beacon pulse. Atstep 1410, the circuitry may be shut down after the fixed time durationhas elapsed. For example, beacon only circuitry 1244 may be put back tosleep.

At step 1412, the EHF communication circuit may check to whether totransition to a new state. It may do this by determining if its CP5 pinhas gone HIGH. If CP5 has not gone HIGH, the process may loop back tostep 1404, thereby enabling the beaconing loop to continue to transmitEHF beacon signals. Moreover, a determination that CP5 has not gone HIGHmay maintain the POC state machine in beacon state 610. If, however, CP5does go HIGH, the process may proceed to step 1414, which may cause theEHF communication unit to activate. For example, all of circuitry 1240may be activated. Moreover, when CP5 goes HIGH, the POC state machinemay progress through states 604, 606, 608, and transition to linktraining state 612.

It is understood that the steps shown in FIG. 14 are merely illustrativeand that additional steps may be added, one or more steps can beomitted, and that the execution order of the steps may vary. Forexample, the determination of whether CP5 goes HIGH can be made at anypoint during the process of FIG. 14.

Reference is now made to FIG. 15. Starting at step 1502, thebeacon/listen tinier may be activated. The beacon/listen tinier may beactivated when the POC state machine enters into the beacon/listen state(e.g., state 610). At step 1504, the beacon/listen tinier can provide apower ON listen pulse on a periodic basis to wake up circuitry thatlistens for an EHF beacon signal. For example, circuitry 1240 may beperiodically woken up. At step 1506, the circuitry may be woken up inresponse to the constant listen pulse received from the beacon/listentimer. The constant listen pulse may, for example, be any one of theconstant listen duration portions of the pulses shown in FIGS. 13A-13D.When circuitry 1240 is woken up, the POC state machine may transitionfrom state 610 to states 604 and 606, and end up in state 608. At step1508, the EHF communication unit may monitor the circuitry for an EHFsignal being received during the constant listen duration. The EHFcommunication unit may listen for the beacon signal while it is in theattentive state (e.g., state 608) and may continue to listen for suchsignals until the power ON listen pulse expires.

At step 1510, a determination is made as to whether at least one EHFsignal is detected during the constant listen pulse. If no EHF beaconsignal is detected, the process may proceed to step 1512, where adetermination is made as to whether the power ON listen pulse hasexpired. If the listen pulse has not expired, the process may loop backto step 1508. If the listen pulse has expired, the process may proceedto step 1514, which may shut down the circuitry that listens for an EHFbeacon signal. The process may loop back to step 1504 when thebeacon/listen timer is ready to turn the circuitry back ON. At step1514, the POC state machine may transition to a listen state (e.g.,listen state 610).

If, at step 1510, an EHF signal is detected, the process may proceed tostep 1516, which may set a stay awake bit (e.g., a bit in stay awakeregister 1250) and activate a stay awake timer (e.g., timer 1260).Moreover, the POC state machine may transition to the link trainingstate in response to an EHF beacon signal detection.

Stay awake timer 1260 may set a time limit duration for which the POCstate machine can exist in any one or more states. The actual time limitmay be set by stay awake register 1250. For example, when the POC statemachine is in the link training state, the POC state machine maytransition back to the beacon/listen state if the stay awake timer timesout before the POC state machine transitions to the capabilities messagestate.

Reference is now made to FIGS. 16-21 to discuss one of several differentapproaches for communicating a capabilities message in accordance withvarious embodiments. When an EHF communication unit is operating as atransmitter unit in the capabilities message state, it may transmit arepeating stream of messages until it receives a rising edge on its CP5pin or if some other condition occurs. A receiver unit, when operatingin the capabilities message state, may wait to receive at least 2consecutive copies of a valid message before transitioning to the nextstate. The message may be transmitted as pulse-width-coded (PWC) symbolsand serialized according to a clock running within the unit. Each symbolcan span a fixed number of clock cycles, begin with a rising edge, endwith a falling edge, and terminate with a 0 level. FIG. 16 shows threedifferent and illustrative symbols that are serialized according tointernal clock 1610.

FIG. 16 shows symbols 1620, 1630, and 1640 each including a rising edge,a falling edge, and terminating with a 0 level. For illustrativepurposes, each symbol may span 12 clock cycles, though it will beappreciated that the symbols may span any suitable number of clockcycles. The symbols can be expressed according to a binary value in eachclock cycle. For example, symbol 1620 may express a binary ‘0’ symbol,symbol 1630 may express a binary ‘S’ symbol, and symbol 1640 may expressa binary ‘1’ symbol. Symbol 1620 may include two clock cycles of 1 levelbinary values, followed by ten clock cycles of 0 level binary valuessuch that a binary ‘0’ symbol can be represented by 110000000000. Symbol1630 may include five clock cycles of 1 level binary values, followed byseven clock cycles of 0 level binary values such that a binary ‘S’symbol can be represented by 111110000000. Symbol 1640 may include nineclock cycles of 1 level binary values, followed by three clock cycles of0 level binary values such that a binary ‘1’ symbol can be representedby 111111111000. Symbols may be gapped by gap cycle 1650, which may notrepresent a symbol, but can be expressed as a 0 level between symbolexpressions. Each gap cycle 1650 may span, for example, one clock cycle.It is understood the binary expression of each symbol is merelyillustrative and that any binary expression may be used for any symbol.It should be understood that other variations of capability messaging ispossible. For example, unique control symbols or characters may be sentin the form of digital bits without specifically using PWC.

The receiver units may be tolerant in accepting clock cycle mismatchesof a fixed percentage of symbols being transmitted by a respectivetransmitter unit. In a system in which there is no common clock or clockrecovery mechanism, the tolerance in clock cycle mismatches allows atransmitter and receiver to be mismatched in clock frequencies and stillreliably communicate. For example, a receiver unit may interpretreceived messages having 1-3 level 1 clock cycles as a 1620 symbol, 4-6level 1 clock cycles as a 1630 symbol, and 7-11 level 1 clock cycles asa 1640 symbol.

FIG. 17 shows an illustrative format of a capabilities message accordingto an embodiment. Capabilities message 1710 can include several fieldsthat can be populated with various symbols. As shown, message 1710 caninclude header field 1720, which may be populated with a fixed number ofsymbols, and several message fields 1730-1735, each of which may bepopulated with various sized bit lengths of symbols. Header field 1720may mark the start of a message. As an illustrative example, four ‘S’symbols may define a header. Each of message fields 1730-1735 can berepresented by any number of bits, shown as X in the FIG. As an example,message fields 1730-1735 may include 16 bits, 16 bits, 16 bits, 2 bits,2 bits, and 28 bits, respectively. The bit lengths are merelyillustrative and any bit length may be used for any one of fields1730-1735. Message field 1730 may specify a key code, which mayrepresent a cipher, an encryption code, or other security related codethat may be verified by a counterpart device. Message field 1731 mayspecify vendor identification. The vendor identification may be storedin a register, read only memory, non-volatile memory, or some otherpermanent storage mechanism within the EHF communication unit. Messagefield 1732 may specify an operating mode of the EHF communicationdevice. The operating mode may specify the data transport mode (e.g.,USB, PCI express, etc.) of the EHF communication device that is set bythe states on one or more of the configuration pins (e.g., pins308-311). In some embodiments, the operating mode may be definedaccording to configuration pin settings of FIG. 3. Message field 1733may specify a particular USB mode functionality (e.g., whether unit is ahost or a slave and on-the-go USB functionality). Message field 1734 mayspecify a transmission band, which may refer to the specific carrierfrequency or carrier frequency offset. Message field 1735 may be afuture expansion field that can be used to communicate additionalcapabilities information for a future application. If desired, messagefield 1735 may be split into two or more fields for future use. It isunderstood that some of the fields may not be used for certainapplications, that some fields may not exist, and other fields may beincluded that are not part of capabilities message 1710.

FIG. 18 shows an illustrative flowchart of steps that may be taken by areceiver unit that is processing a received capabilities messageaccording to an embodiment. Beginning with step 1802, a capabilitiesmessage may be received. The capabilities message may be transmitted bya counterpart transmitter unit according to capabilities messagingformat, such as that illustrated above in connection with FIG. 17. Assuch, the received capabilities message may include a key code, vendoridentification, and an operating mode. If the operating mode is a USBmode, the capabilities message may also include USB functionalityinformation. The receiver unit may have stored therein, or programmedtherein, its own local capabilities message information. For example,the receiver unit may have vendor information, operating modeinformation, and optional USB functionality information. At step 1804, adetermination is made as to whether the received vendor identificationis the same as the local vendor identification. If they are not thesame, the process proceeds to step 1806, and if they are same theprocess proceeds to step 1808. At step 1806, verification of thecapabilities message may cease, thereby causing the POC state machine toexit out of its progression and restart.

At step 1808, which is the next step once the vendor identification isverified in step 1804, a determination is made as to whether thereceived operating mode can validly operate with the local operatingmode. In some applications, the received operating mode and localoperating mode may be the same, which would result in a valid operationamong the received and local operating modes. In other applications, thereceived and local operating modes may be different, such as is the casewith various USB modes. Some different USB modes may validly worktogether and others may not. FIG. 19 shows an illustrative table showingwhich USB modes validly work together and which do not. The EHFcommunication unit may access this table when making the determinationat step 1808. As shown in FIG. 19, there is a Received Mode column, aLocal Mode column, and a Result column. The result column indicateswhether the USB modes identified in the same row can validly worktogether. The USB modes can include USB 2.0, USB 3.0, and USB 3/2 Auto.USB 3/2 Auto may be switchable USB mode that automatically resolves touse either USB 2.0 or USB 3.0 depending on various factors, asdetermined by the USB specification.

Referring back to FIG. 18, if, at step 1808, the determination is thatboth modes cannot validly work together, the process proceeds to step1806, where the capabilities verification ends. If the determination isthat both modes can operate together, the process proceeds to step 1810.At step 1810, a determination is made as to whether the operating modeis a USB mode. If the operating mode is not a USB mode, the processproceeds to step 1812. At step 1812, the received capabilities messagemay be considered verified and the POC state machine may be advanced tothe next transition state (e.g., hold off state, followed by the datatransport state). If, at step 1810, it is determined that the operationmode is a USB mode, the process may proceed to step 1814.

At step 1814, the receiver unit may compute a local code for its USBfunctionality mode. This local code may represent whether the device isa USB client, USB host, USB OTG client, or USB OTG host. This local codemay occupy the USB functionality field of a capabilities message. Thereceiver may calculate its local code by sampling the states of one ofthe configuration pins (e.g., pin 308) during different stages of thePOC state machine and comparing the sampled states to compute the localcode. For example, the unit may register the state of one of theconfiguration pins (e.g., pin 308) during the attentive state and thecapabilities message state. The registered states are compared tocompute the local code. FIG. 20 shows an illustrative lookup table thatmay be accessed to compute the local code. Referring now to FIG. 20,values are shown for the configuration pin in the attentive state andthe capabilities message state. The values can include 0, 1, FLOAT, andX, which may be akin to a don't care. Thus, as shown, when the pin is 0at attentive, the computed code may be 00. In another case, when the pinis 1 at attentive, the computed code may be 01. In these two cases, thevalue of the pin at capabilities message state is not taken intoaccount. If the pin is FLOAT at attentive state and 1 at capabilitiesmessage state, then the computed code may be 11. If the pin is FLOAT atattentive state and 0 or FLOAT at capabilities message state, then thecomputed code may be 10. The computed code can specify the USB modefunctionality of the EHF communication unit and it's active connectionto a host device. For example, local code of 00 may indicate USB hostonly mode, a local code of 01 may indicated a USB client only mode, alocal code of 10 may indicate an on-the-go Host mode, and a local codeof 11 may indicate an on-the-go client mode.

It should be appreciated that a transmitter unit may access the sametable as shown in FIG. 20 to determine its USB mode functionality. Uponcomputing its USB mode functionality, it may include the appropriatecode in the capabilities message it transmits to the receiver unit. Inparticular, it may include that code in message field 1733 of message1710.

Referring back to FIG. 18, at step 1816, the received USB modefunctionality code is compared to the local USB functionality code.Then, at step 1818, an action may be performed based on the comparisonof the received code and the local code. For example, FIG. 21 showsillustrative actions that may be taken based on comparisons of thereceived code and the local code. As shown, some of the comparisonresults can result in determination of an invalid capabilities message,which can cause the POC state machine to drop out of the capabilitiesmessage state and revert back to beacon/listen state. As also shown,some of the comparisons can result in determination of a validcapabilities message. Responsive to a valid capabilities message, thePOC state machine may advance to the next state (e.g., hold off stateand/or data transport state). Some actions may also include driving oneof the configuration pins (e.g., pin 308) to a logic 0 or 1.

It is understood that the steps shown in FIG. 18 are merely illustrativeand that the order in which steps are performed can be rearranged,additional steps may be added, and steps may be omitted. For example,steps may be added to compare a received key code to a local key code toassess the validity of the received capabilities message. In addition,additional authentication may be performed during the capabilitiesmessage state.

Reference is now made to FIGS. 22-29 for additional discussion on thedata transport modes in accordance with various embodiments. Asdiscussed above, the data transport mode for an EHF communication chipis set based on the states of its configuration and control pins (e.g.,pins 308-313). When several of such EHF communications chips are used inconjunction with each other, they may enable chip-to-chip contactlesscommunication according to the selected data transport mode. FIGS. 22-29show different connection diagrams for implementing various datatransport modes. Each of the communication units shown in these FIGS.may include an EHF communication unit such as that shown in FIG. 3, andas such, similar component and pin designations may be referred toduring the discussion of these FIGS.

FIGS. 22A-22C show different connection diagrams for EHF chipsconfigured to operate according to one of several different USB modesaccording to various embodiments. FIG. 22A shows an illustrativeconnection diagram for a USB 3.0 transport mode. As shown, the highspeed data pins are being utilized by each EHF unit. In particular,Super Speed (SS) transmission data, shown as SSTX+/−, may be provided totransmitter unit 2202 via those high speed pins. Unit 2202 maycontactlessly transmit that data to receiver unit 2212, which outputsthat data via its high speed pins. Super Speed (SS) receive data, shownas SSRX+/−, may be provided to transmitter unit 2214 via high speedpins. Transmitter unit 2214 may contactlessly transmit that receiveddata to receiver unit 2204, which outputs that data via its high speedpins. The CP5 and CP6 pins can be wired as shown.

FIG. 22B shows an illustrative connection diagram for a USB 2.0 datatransport mode. As shown, the low speed data pins are being utilized byeach EHF unit. In particular, transmission data, shown as D+/−, may beprovided to transmitter unit 2202 via those low speed pins. Unit 2202may contactlessly transmit that data to receiver unit 2212, whichoutputs that data via its low speed pins. Receiver data, shown as D+/−,may be provided to transmitter unit 2214 via low speed pins. Transmitterunit 2214 may contactlessly transmit that received data to receiver unit2204, which outputs that data via its low speed pins. The low speedpins, CP5 pins and, CP6 pins can be wired as shown.

FIG. 22C shows an illustrative connection diagram for a USB 3.0/2.0 AutoSwitchable data transport mode. As shown, the connection diagram may bea combination of both USB 3.0 and 2.0 transport modes. The high speedpins, low speed pins, CP5 pins and, CP6 pins can be wired as shown. Inthis mode, either USB 3.0 or USB 2.0 may be selected for data transport,depending on the result of the capabilities message and other inputparameters.

FIGS. 23A and 23B show different connection diagrams for EHF chipsconfigured to operate according to one of several different Display Portmodes according to various embodiments. FIG. 23A shows an illustrativeconnection diagram for a DisplayPort transport mode and an embeddedDisplayPort mode. The EHF chips can be designated as a source or sink,as identified by one of the configuration pins (e.g., CP4 pin 311). Anysuitable number of EHF chips (e.g., typically 4 chips) may serve as mainlinks and another EHF chip may serve as an auxiliary link. Only two mainlinks are shown and each may receive and/or output data on its highspeed pins. Data may pass transparently over the high speed pins. On thesink side, the main link 0 may have its low speed data pin tied to “0”and the main links 1-3 may have their low speed data pins tied to “1”.The CP6 and CP5 pins may be connected as shown.

The auxiliary link may operate in a half-duplex, direction-reversingmode of operation. EHF units using the auxiliary link may use their lowspeed data pins for data I/O and one of their configuration pins (e.g.,CP1 pin 308) for a hot plug detect (HPD).

FIG. 23B shows an illustrative connection diagram for a MyDP transportmode. The connection diagram for a MyDP shows a single Main link and anauxiliary link. The main links are tied to the high speed pins (of thehost device), as shown. The sink side of the auxiliary link has one ofits configuration pins (e.g., CP1 pin 308) tied to logic HIGH and theauxiliary data tied to both low speed pins. The source side of theauxiliary link has one of its configuration pins (e.g., CP1 pin 308)left floating and the auxiliary data is tied to just one low speed pin.The CP5 and CP6 pins can be connected as shown.

FIG. 24 shows a connection diagram for EHF chips configured to operateaccording to a SATA or SAS data transport mode. As shown, the connectiondiagram is similar to the USB 3.0 connection diagram of FIG. 22A, withdifferences in data being provided to and/or outputted from the EHFcommunication units.

FIG. 25 shows a connection diagram for EHF chips configured to operateaccording to a multi-lane data transport mode, such as PCIe. As shown,the connection diagram is similar to the USB 3.0 connection diagram ofFIG. 22A, with differences in data being provided to and/or outputtedfrom the EHF communication units, and that multiple instances of thesame groups of units are being used. As shown, N lanes of data may beimplemented using PCIe transport mode, and each lane may require it ownfull duplex set of EHF units.

FIG. 26 shows a connection diagram for EHF chips configured to operateaccording to an Ethernet data transport mode, such as the GigabitEthernet using the SGMII (serial gigabit media independent interface).As shown, the connection diagram is similar to the USB 3.0 connectiondiagram of FIG. 22A, with differences in data being provided to and/oroutputted from the EHF communication units. In addition, FIG. 26 showsthe physical layer of the Ethernet.

FIG. 27 shows a connection diagram for EHF chips configured to operateaccording to an I2S data transport mode. As shown, the units may beassociated with a master or a slave. For example, the master may beassociated with devices such as a media player or a telephone, and theslave may be associated with devices such as headphones, a microphone,or a headset. A master transmitter unit may receive serial clock (SCK),serial data (SD), and word sync (WS) signals on its configuration pin(e.g., CP1 pin 308) and low speed pins, respectively. The slave receiverunit may output those same signals to the output pins. The SD and WSsignals are clocked into a register with the SCK signal in the slavedevice, and the register may be asynchronously over-sampled with aninternal clock in the slave device.

A slave transmitter unit may transmit SD signals (e.g., input signals ormicrophone signals) received on one of its low speed data pins to amaster receiver unit. The slave transmitter unit and the master receiverunit, as shown here, may operate according to a generic low speed mode,which may be a mode for asynchronously transmitting data. Moreover, inthe generic low speed mode, data may be passed transparently through theEHF communication units. In the transmitter device, data is received onone of the low speed data pins and mapped to a 2 level EHF signalingwith ‘1’ mapped to full carrier and ‘0’ mapped to partial carrier. Areceiver device may receive the 2 level EHF signal and reproduce theoriginal binary stream on one of its low speed data pins.

FIGS. 28A-28C show different connection diagrams for EHF chipsconfigured to operate according to a GPIO or 12C transport modeaccording to various embodiments. In particular, FIG. 28A shows aconnection diagram of EHF units wired for a bi-directional GPIOtransport mode and FIG. 22B shows a connection diagram of EHF unitswired for unidirectional GPIO transport mode. In both of these modes,the low speed pins and one of the configuration pins (e.g., CP1 pin 308)are used as I/O pins. The I/Os of the receiver units in the host device(not shown) may behave as open-drain outputs with fixed resistanceinternal pull-ups. The I/Os of the transmitter units in the host device(not shown) may function as 2 state inputs.

FIG. 28C shows a connection diagram of EHF units wired for a I2Ctransport mode. This mode may operate similar to the GPIO mode, but onlyone of the low speed pins is used and the same configuration pin isused. In addition, external resistance pull-ups (e.g., R1 or R2) can beused in lieu of the internal resistance pull-ups. A complete link may beformed using the units in I2C mode to transport SDA (data) and SCK(clock) master-to-slave, and units in a generic low-speed mode totransport SDA from slave-to-master. In order for the generic low speedmode to be used in support of a I2C transport mode, the low speed pin(e.g., LSD_c pin) on the receiver unit may function as a open-drainoutput that connected to the input open-drain low speed data pin (e.g.,LSD_t pin) of the transmitter unit. These pins may be connected togetherand externally connected to VDD through a resistor.

FIG. 29 shows a connection diagram for EHF chips configured to operateaccording to a generic data transport mode that does not require aprogression of consciousness. This mode may function similar to ageneric low speed mode, except that the POC state machine may transitionfrom the CP4 state (e.g., CP4 state 606) to the data transport state(e.g., state 618), thereby bypassing the attentive, link training, andcapabilities message states. Such a transition is akin to transition 19of FIG. 6. In addition, there may be no exit from the data transportstate except for a transition to the OFF state. This mode may be used asa stand-alone link that is managed by a microcontroller. The CP6 inputmay enable EHF on a transmitter unit, and may indicated presence of EHF(either a 0 or a 1) on a receiver unit. For example, when CP6 is HIGH ona transmitter unit, data may be sent as 1 or 0 via EHF signaling,otherwise an EHF Idle signal may be transmitted. The EHF idle signal maybe similar to the “keep alive pulse” as discussed above.

Reference is now made to FIGS. 30-32 to discuss in more detail the datatransport idle state according to various embodiments. FIG. 30 shows anillustrative flowchart of steps that may be taken by a transmitter unitduring the data transport idle state. FIG. 31 shows an illustrativeflowchart of steps that may be taken by a receiver unit during the datatransport idle state. FIG. 32 shows illustrative timing diagrams of adata transport idle keep alive cycle. In general, as previouslydiscussed above, the data transport idle state may enable quick entryand exit low power states for one or more data transport modes (e.g.,USB 2.0, USB 3.0, and DisplayPort).

Beginning with step 3002 in FIG. 30, a transmitter unit may have enteredinto a data transport idle state. The conditions for entering into thedata transport idle state were discussed above in connection with FIG.6. At step 3004, various circuitry, including circuitry operative fortransmitting EHF signals, may be powered down. In some embodiments, thecircuitry being shut down can be the same circuitry that is powered downduring when the unit is in the beacon/listen state. Then, at step 3006,a keep alive timer may be activated. The keep alive timer mayperiodically wake up the powered down circuitry to enable that circuitryto transmit an EHF keep alive pulse signal (discussed below). At step3008, circuitry may wake up responsive to an instruction from the keepawake timer, and at step 3010, that circuitry may transmit the EHF keepalive pulse. The EHF keep alive pulse may include a series of 1's thatspan a fixed number of clock cycles (e.g., 16 clock cycles) every fixedperiod of time (e.g., every 3.125p). Examples of this EHF keep alivepulse are shown in FIG. 32. After the EHF keep alive pulse istransmitted, the circuitry is shut down, as indicated by step 3012.After the circuitry is shutdown, the process may loop back to step 3008.The transmitter unit may continue transmitting EHF keep alive pulsesuntil it returns to the data transport state or the beacon/listen state.These transitions are now discussed.

The flowchart may have two other loops that are running concurrent withthe keep alive timer loop. For example, one of the other loopstransitions to step 3020 from step 3002. At step 3020, a determinationis made as to whether any data is received on an input buffer. Forexample, the transmitter unit may determine whether any data has beenreceived on it high speed or low speed data pins. If no data isreceived, the process loops back to step 3020. If data is received, thetransmitter unit may enter into the data transport state.

The other one of the loops begins at step 3030. At step 3030, adetermination is made whether the transmitter unit's CP6 pin has gone to‘0’. If not, the process proceeds to step 3032, which determines whetherthe transmitter unit's CP5 pin has remained at 0 for a certainpredefined period of time. If not, the process proceeds back to step3030. If, at step 3030, the determination was yes, the process mayproceed to step 3034, which may cause the unit to enter into thebeacon/listen state. If, at step 3032, the determination is yes, theprocess may proceed to step 3034.

Beginning with step 3102 in FIG. 31, a receiver unit may have enteredinto a data transport idle state. The conditions for entering into thedata transport idle state were discussed above in connection with FIG.6. At step 3104, various circuitry, including circuitry operative to fordetecting presence of EHF signals, may be powered down. In someembodiments, the circuitry being shut down can be the same circuitrythat is powered down during when the unit is in the beacon/listen state.Then, at step 3106, a listen timer may be activated. The listen timermay periodically wake up the powered down circuitry to enable thatcircuitry to listen for EHF signals. At step 3108, circuitry may wake upresponsive to an instruction from the listen timer, such that thecircuitry can listen for EHF signals during a constant listen timeperiod every fixed period of time. The constant listen time period maybe set by the listen timer. For example, the listen time may cause thecircuitry to listen for EHF signals for 6.25 μs every 125 μs. Anexamples of this receiver listen pulse is shown in FIG. 32.

At step 3110, a determination is made as to whether any EHF signals havebeen received. If no EHF signals have been received, the process mayproceed to step 3112, which checks whether a time out timer has timedout. The time out timer may control whether receiver should transitionto the beacon/listen state due to non-occurrence of EHF activity. Thus,if the time out timer has timed out, then the receiver unit may enterthe beacon/listen state, as shown in step 3116, but if the timer has nottimed out, the process may proceed to step 3114. At step 3114, thecircuitry may be powered down, and the process may loop back to step3108. If, at step 3110, EHF signals have been received, the process mayproceed to step 3118.

At step 3118, a determination is made whether the received EHF signalsare indicative of a keep alive pulse or a non-idle pulse. Thisdetermination may be based on a burst length of the received EHFsignals. The received EHF signals may include a series of 1's and/or 0'sthat are grouped together to form a burst. If the burst length of thereceived signals exceeds a non-idle time threshold, then the receivedEHF signals may be classified as a non-idle pulse and the process canproceed to step 3124 and then enter into the data transport state, atstep 3126. If the burst length of the received signals includes a burstof 1's that falls within a keep alive pulse time range, then thereceived EHF signals may be classified as a keep-alive pulse. The keepalive pulse time range may include a lower time bound and an upper timebound centered around the pulse length of the EHF keep-alive pulsesignal. For example, if the pulse length of the EHF keep-alive pulsesignal is 60 ns, the lower time boundary may be 40 ns and the upper timeboundary may be 80 ns. The idle time threshold may be greater than theupper time boundary of the keep alive pulse range. For example, the idletime threshold may be 1.2 ns. Upon determining that the received EHFsignals are keep-alive pulse, the process may proceed to step 3120, andthen proceed to step 3122, which resets the time out timer, beforelooping back to step 3108.

FIG. 32 shows illustrative timing diagrams of an idle keep-alive cyclefor both transmitter and receiver units. The Tx cycle shows illustrativekeep-alive pulses having a pulse width of about 60 ns every 3.125 ns.The Rx cycle shows illustrative listen cycle in which the receivercircuitry listens for EHF signals during the constant listen period forevery listen cycle.

Reference is now made to FIGS. 33-36 to discuss an alternative approachto establishing an EHF communications link between two EHF communicationunits, according to an embodiment. This alternative approach differsfrom the approach discussed above in connection with FIG. 9 in that thewake up loop only requires two EHF communication units to establish anEHF communications link. This approach eliminates the need for a wake uploop to use both wired and contactless connections to communicate dataand signals between EHF communications units. Thus, in this approach thetwo EHF communication units may directly communicate with each otherusing contactless EHF signals to establish the link.

FIG. 33 illustrates a communications system 3300 wherein two electronicdevices 3310 and 3320 may communicate with one another over acontactless communications link, according to an embodiment. System 3300may be similar to systems 100 and 200 in many respects. First device3310 may include EHF communication unit 3312 and host system 3316. Hostsystem 3316 may communicate with EHF communication unit 3312. Similarly,second device 3320 may include EHF communication unit 3322 and hostsystem 3326. Host system 3326 may communicate with EHF communicationunit 3322. Host systems 3316 and 3326 may be similar to host systems 104and 124, both of which include circuitry specific to their respectivedevices and thereby enable devices 3310 and 3320 to operate for theirintended functionality.

In some embodiments, each of EHF communication units 3312 and 3324 canbe the same as EHF communication unit 106 or 126, discussed above. Assuch, EHF communication units 3312 and 3324 include transceivers capableof transmitting and receiving EHF signals, and thus can conductbi-directional EHF communications. This bi-directional EHFcommunications link is shown as contactless communications link 3330. Asalso shown, a single link wake-up loop only includes EHF communicationunits 3312 and 3322, and link 3330.

In order for devices 3310 and 3320 to communicate with each other vialink 3330, EHF units 3312 and 3322 may have to progress through a seriesof steps before data can be transferred between the devices. These stepsmay be controlled by one or more state machines. The state machines maybe similar to the progression of consciousness (POC) state machine, asdiscussed above. In some embodiments, each of units 3312 and 3322 mayprogress through the same states as POC state machine, but differ in howstate change notifications are provided and the conditions forsatisfying one or more of the states may also be different. For example,the POC state machine operating in connection with the system of FIG. 9uses wired paths to communicate state notifications, whereas a POC statemachine operating in connection with FIG. 33 does not use any wiredpaths to communicate state notifications, but only uses communicationslink 3330 to provide state change notifications. Moreover, because nowired paths are being used to propagate state changes, EHF communicationunits 3312 and 3322 may take turns transmitting and receiving EHFsignals over communications link 3330.

The single link wake-up loop employed in system 3300 may require each ofEHF communication units 3312 and 3322 to switch between transmitter andreceiver modes. For example, if a unit (e.g., 3313) is in a first stateand is transmitting data via link 3330, that unit may operate in atransmitter mode to transmit the data for a first period of time, andthen switch to a receiver mode to listen for data that may transmittedby the other unit for a second period of time. After the second periodof time lapses, the unit may switch back to the transmitter mode, andrepeat this cycle until a condition is satisfied that causes the unit toswitch to a different state. For example, the unit may transition to adifferent state if a notification is received when it is operating inthe receiver mode.

FIG. 34 shows an illustrative timing diagram showing the POC states ofunits 3310 and 3320 and the transmitter and receiver modes of operation,according to an embodiment. As shown, units 3322 and 3312 transitionthrough the beaconing or listening, link training, capabilities message,and data transport states. For each state, the timing diagram shows theTx and Rx modes of operation for each unit. The Tx and Rx modes ofoperation are merely illustrative, however, the FIG. does show how eachunit can switch between modes during one or more states. In addition,the modes of operations illustrate how each unit operates itstransceiver in order to progress through its respective POC statemachine. For example, unit 3322 is shown to switch between modes in thebeaconing state. In the transmit mode, unit 3322 may transmit an EHFsignal, and in the receive mode signal, unit 3322 may listen for asignal to determine whether to transition to the link training state.Continuing with this example, unit 3312 may be in a listen state,wherein in a receive mode it listens for EHF signals, and in a transmitmode, it can transmit an EHF signal acknowledging it has received theEHF signals. It may also transition to the link training state. Whenunit 3322 receives the acknowledgment signal from unit 3312, it too maytransition to the link training state. This cycle of switching betweenmodes to advance through states may continue until both units enter intothe data transport state or fail out of progression due to one or morefactors.

FIG. 35 shows an illustrative flowchart of steps that may be taken by anEHF communication unit (e.g., unit 3322) that is operating primarily asa transmitter unit according to an embodiment. It is understood thatalthough this unit is operating primarily as a transmitter unit, it canalso operate as a receiver unit to receive signals from another unit(e.g., unit 3312). Starting at step 3502, a beacon signal can betransmitted by an EHF communication unit (e.g., unit 3322). Here, theunit is operating in a transmitter mode. At 3504, the EHF unit maylisten for an EHF response from another unit (e.g., unit 3312). Here theunit is operating in a receiver mode. At step 3506, a determination ismade whether an EHF response is received. If NO, the flowchart revertsback to step 3502. If YES, the flowchart proceeds to step 3508, wherethe EHF unit can transmit link training data. In this step, the unit isoperating in a transmitter mode.

At step 3510, a determination is made as to whether an EHF response isreceived. In this step, the unit is operating a receiver mode. If thedetermination is NO, the process proceeds to step 3512, which makes adetermination if a timer has timed out. If the timer has not timed out,the process returns to step 3508. If the timer has timed out, theprocess can return to step 3502. If the determination at step 3510 isYES, the process can proceed to step 3514, where the EHF unit transmitsa capabilities message. At step 3516, a determination is made whether anEHF response is received. If the determination is NO, the process canproceed to step 3518, which makes a determination if a timer has timedout. If the timer has not timed out, the process returns to step 3514.If the timer has timed out, the process can return to step 3502. If thedetermination at step 3516 is YES, the process can proceed to step 3514,where the unit can enter into a data transport state.

FIG. 36 shows an illustrative flowchart of steps that may be taken by anEHF communication unit (e.g., unit 3312) that is operating primarily asa receiver unit according to an embodiment. It is understood thatalthough this unit is operating primarily as a receiver unit, it is canalso operate as a transmitter unit to receive signals from another unit(e.g., unit 3322). Starting at step 3602, an EHF unit can listen for abeacon signal. In this step, the EHF unit may be operating in a receivermode. At step 3604, the EHF unit may switch to a transmitter mode andtransmit an EHF response signal when the beacon signal is detected. Atstep 3606, the EHF unit may switch back to a receiver mode and wait fora link training signals to be received. At step 3608, the EHF unit mayswitch to a transmitter mode and transmit an EHF response signal when alink is trained.

At step 3610, the EHF unit may switch back to the receiver mode and waitfor a capabilities message to be received. At step 3612, the EHF unitmay switch to the transmitter mode and transmit an EHF response signalwhen the capabilities message is validated. At step 3614, the unit mayenter into the data transport state.

Paragraph 1: A system including:

-   -   first and second devices each including a plurality of        contactless communication units,    -   wherein each communication unit is operative to execute its own        state machine to enable at least one contactless communications        link between the first and second devices, and    -   wherein the state machines transition their respective        communication units through a plurality of states to establish        at least one contactless communications link.

Paragraph 2: The system of paragraph 1, wherein a wake up loop definingupstream and downstream relationships exists among the plurality ofcontactless communication units.

Paragraph 3: The system of paragraph 2, wherein the upstreamcommunication unit provides a signal to a downstream communication unit.

Paragraph 4: The system of paragraph 3, wherein when the upstreamcommunication unit is a transmitter unit, and the downstreamcommunication unit is a receiver unit, the signal is communicated via anextremely high frequency (EHF) contactless connection.

Paragraph 5: The system of paragraph 3, wherein when the upstreamcommunication unit is a receiver unit, and the downstream communicationunit is a transmitter unit, the signal is communicated via a wiredconnection.

Paragraph 6: The system of paragraph 2, wherein a state transition ofany downstream communication unit depends on a signal of it upstreamcommunication unit.

Paragraph 7: The system of paragraph 1, wherein a failure to satisfy acondition for any state transition for any state machine causes thatstate machine to revert back to an initialization state.

Paragraph 8: The system of paragraph 1, wherein the plurality of statescomprises an initialization state, a link training state, a capabilitiesmessage state, and the data transport state.

Paragraph 9. The system of paragraph 8, wherein the initialization statecomprises a beaconing state.

Paragraph 10: The system of paragraph 8, wherein the initializationstate comprises a listening state.

Paragraph 11: A system including:

-   -   a plurality of contactless communication units arranged in a        wake up loop via a combination of wired and contactless        connections; and    -   wherein each contactless communication unit uses the wake up        loop to transition through a plurality of states to establish at        least one EHF communications link.

Paragraph 12: The system of paragraph 11, further including:

-   -   a first device comprises at least two of the plurality of        contactless communication units; and    -   a second device including at least two of the plurality of        contactless communication units, wherein the wired connections        enable intra-device communication among the communication units,        and wherein the contactless connections enable inter-device        communication among the communication units.

Paragraph 13: The system of paragraph 12, wherein the at least two ofthe plurality of contactless communication units of the first devicecomprise a first receiver unit and a first transmitter unit, wherein thefirst receiver and transmitter units communicate with each other via atleast a first wired connection,

-   -   wherein the least two of the plurality of contactless        communication units of the second device comprise a second        receiver unit and second transmitter unit, wherein the second        receiver and transmitter units communicate with each other via        at least a second wired connection,    -   wherein the first transmitter unit communicates with the second        receiver unit via a first contactless connection, and wherein        the second transmitter unit communicates with the first receiver        unit via a second contactless connection.

Paragraph 14: The system of paragraph 11, wherein execution of a statetransition for any communication unit depends on a signal provided by anupstream communication unit arranged immediately before it according tothe wake up loop.

Paragraph 15: The system of paragraph 14, wherein when the upstreamcommunication unit is a transmitter unit, the transmitter unitcommunicates the signal via the contactless connection.

Paragraph 16: The system of paragraph 14, wherein when the upstreamcommunication unit is a receiver unit, the receiver unit communicatesthe signal via the wired connection.

Paragraph 17: The system of paragraph 11, wherein the plurality ofstates comprises a link training state, a capabilities messaging state,and a data transporting state.

Paragraph 18: A contactless communications receiver unit (CCRU) for usein establishing a contactless communications link with a firstcontactless communications transmitter unit and for use in communicatingwith at least a second contactless communications transmitter unit viaat least one wired path, the contactless communication receiver unitincluding:

-   -   a plurality of pins, wherein at least a first pin is used to        communicate with the second transmitter unit via a wired path;    -   a transducer for receiving extremely high frequency (EHF)        contactless signals from the first transmitter unit; and    -   circuitry operative to:        -   execute a CCRU state machine that tracks a state of the CCRU            during the establishment of the contactless communications            link, wherein the state machine transitions through a            plurality of states in response to signals received by the            transducer; and        -   selectively drive a signal on the at least one pin used to            communicate with the second transmitter unit in response to            a state transition.

Paragraph 19: The contactless communications receiver unit of paragraph18, wherein the plurality of states comprises a link training state, acapabilities state, and a data transport state.

Paragraph 20: The contactless communications receiver unit of paragraph19, wherein the state machine transitions to the link training statewhen the transducer receives a beacon signal.

Paragraph 21: The contactless communications receiver unit of paragraph19, wherein the state machine transitions to the capabilities after thecontactless communications link between the CCRU and the firstcontactless communications transmitter unit is trained.

Paragraph 22: The contactless communications receiver unit of paragraph19, wherein the state machine transitions to the data transport stateafter a capabilities message is received from the first contactlesscommunications transmitter unit and validated by the CCRU.

Paragraph 23: The contactless communications receiver unit of paragraph22, wherein the plurality of states comprise a holdoff state, whereinthe state machine transitions from the capabilities message state to theholdoff state before transitioning to data transport state.

Paragraph 24: The contactless communication receiver of paragraph 19,wherein the plurality of states comprise a data transport idle state,wherein the state machine transitions from the data transport state tothe data transport idle state to save power.

Paragraph 25: The contactless communications receiver unit of paragraph19, wherein the plurality of states comprise at least one initializationstate, and wherein the circuitry is operative to drive a signal on asecond pin that is used to communicate with the second transmitter unitin response to state transition from the at least one initializationstate to the link training state.

Paragraph 26: The contactless communications receiver unit of paragraph18, wherein the plurality of pins comprise at least one transport modeselection pin, wherein the contactless communications link transportsdata according to a transport mode set by the at least one transportmode selection pin.

Paragraph 27: The contactless communications receiver unit of paragraph19, wherein the data transport mode is a standards based transport mode.

Paragraph 28: A contactless communications transmitter unit (CCTU) foruse in establishing a contactless communications link with a firstcontactless communications receiver unit and for use in communicatingwith a second contactless communications receiver unit via at least onewired path, the contactless communication transmitter unit including:

-   -   a plurality of pins, wherein at least one pin is used to        communicate with the second receiver unit via a wired path;    -   a transducer for transmitting extremely high frequency (EHF)        contactless signals to the first receiver unit;    -   circuitry operative to:        -   execute a CCTU state machine that tracks a state of the CCTU            during the establishment of the contactless communications            link, wherein the state machine transitions through a            plurality of states in response to signals received by the            at least one pin; and        -   selectively transmit EHF signals, using the transducer, in            response to a state transition.

Paragraph 29: The contactless communication transmitter unit ofparagraph 28, wherein the at least one pin is used to communicate withthe second receiver unit via the wired path is an inter chipcommunications pin.

Paragraph 30: The contactless communication transmitter unit ofparagraph 29, wherein the inter chip communications pin receives asignal that causes the state machine to transition to a new state.

Paragraph 31: The contactless communications transmitter unit ofparagraph 28, wherein the selectively transmitted EHF signal determinesa future state of the state machine.

Paragraph 32: The contactless communications transmitter unit ofparagraph 28, wherein a signal received by the at least one pin isderived from a state change transition in the CCTU state machine.

Paragraph 33: The contactless communications transmitter unit ofparagraph 28, wherein the CCTU is part of a wake up loop including atleast the first and second receiver units, the CCTU, and a secondtransmitter unit, the second transmitter operatively coupled to thefirst and second receiver units.

Paragraph 34: The contactless communications transmitter unit ofparagraph 33, wherein the CCTU state machine uses the wake up loop toadvance state change transitions.

Paragraph 35: The contactless communication transmitter unit ofparagraph 28, wherein the plurality of states comprises at least oneinitialization state, wherein one of the plurality of pins is a beaconenable pin, and wherein when the beacon enable pin is driven HIGH, thestate machine transitions to the at least one initialization state.

Paragraph 36: The contactless communication transmitter unit ofparagraph 35, wherein when the beacon enable pin is driven LOW, thestate machine transitions to an OFF state.

Paragraph 37: The contactless communication transmitter unit ofparagraph 35, wherein the at least one initialization state comprises abeaconing state that causes the circuitry to emit a beaconing EHF signalvia the transducer.

Paragraph 38: The contactless communication transmitter unit ofparagraph 28, wherein the plurality of states comprises a link trainingstate, a capabilities state, and a data transport state.

Paragraph 39: A method for establishing an EHF communications link;including:

-   -   executing a state machine that tracks a state of a first EHF        communication unit to establish the EHF communications link, the        state machine operative to transition through a plurality of        states responsive to signals provided by an upstream EHF        communication unit, wherein executing the state machine        comprises:        -   determining whether to transition to a selected one of the            plurality of states in response to a signal received by the            upstream EHF communication unit;        -   transitioning to the selected state when it is determined to            transition to the selected state; and        -   communicating a signal to a downstream EHF communication            unit in response to the state transition.

Paragraph 40: The method of paragraph 39, wherein the first, upstream,and downstream communication units are included as part of a wake uploop.

Paragraph 41: The method of paragraph 40, further including using thewake up loop to transition through the plurality of states.

Paragraph 42: The method of paragraph 39, wherein the signalcommunicated to the downstream EHF communication unit determines afuture state of the state machine.

Paragraph 43: The method of paragraph 39, wherein executing the statemachine comprises transitioning to a beacon/listen state when it isdetermined not to transition to the selected state.

Paragraph 44: The method of paragraph 39, wherein executing the statemachine comprises transitioning to a serial interface control mode.

Paragraph 45: The method of paragraph 39, wherein the selected statecomprises a link training state.

Paragraph 46: The method of paragraph 45 further including transmittinglink training data to the downstream communication unit.

Paragraph 47: The method of paragraph 45 further including:

-   -   receiving link training data from the upstream communication        unit; and    -   calibrating the first communication unit based on the received        link training data.

Paragraph 48: The method of paragraph 39, wherein the selected statecomprises a capabilities message state.

Paragraph 49: The method of paragraph 48 further including transmittingcapabilities message data to the downstream communication unit.

Paragraph 50: The method of paragraph 48 further including:

-   -   receiving capabilities message data from the upstream        communication unit; and    -   validating the received capabilities message data.

Paragraph 51: The method of paragraph 39, wherein the selected statecomprises a data transport state.

Paragraph 52: The method of paragraph 39 further including:

-   -   determining a data transport mode for use with the        communications link;    -   contactlessly transporting data according to the data transport        mode using an established communications link.

Paragraph 53: The method of paragraph 39 further including:

-   -   periodically activating circuitry to perform one of a beaconing        operation and a listening operation.

Paragraph 54: A method for using an extremely high frequency (EHF)communication unit to transmit an EHF beaconing signal, the EHFcommunication unit including a timer and circuitry operative to transmitthe EHF beaconing signal, the method including:

-   -   activating the timer in response to the EHF communication unit        entering a beaconing state, wherein the timer is operative to        provide a pulse once a period to periodically wake up the        circuitry that transmits the EHF beaconing signal, wherein the        pulse has a fixed time duration;    -   waking up the circuitry in response to the pulse provided by the        timer;    -   transmitting, from the circuitry, the EHF beaconing signal for        the fixed time duration;    -   shutting down the circuitry after the fixed time duration has        elapsed; and    -   repeating a sequence including the waking up, the transmitting,        and the shutting down.

Paragraph 55: The method of paragraph 54, wherein the EHF beaconingsignal is an EHF contactless signal including a logic value of HIGH.

Paragraph 56: The method of paragraph 54, wherein the timer operatesaccording to a selected one of a plurality of different clock speeds,wherein the fixed time duration remains the same regardless of theselected clock speed.

Paragraph 57: The method of paragraph 54, wherein the timer operatesaccording to a selected one of a plurality of different clock speeds,wherein the period changes based on the selected clock speed.

Paragraph 58: The method of paragraph 57, wherein the period is based ona fixed number of clock cycles.

Paragraph 59: The method of paragraph 58, wherein the fixed number ofclock cycles is a fraction of a second fixed number of clock cycles thatdefines a constant listening period of a counterpart EHF communicationunit that receives the EHF beaconing signal.

Paragraph 60: The method of paragraph 54, wherein the sequence isrepeated until the EHF communication unit is instructed to ceasetransmitting the beaconing signal.

Paragraph 61: The method of paragraph 54, further including:

-   -   receiving an indication that a counterpart EHF communication        unit has received the transmitted EHF beaconing signal; and    -   ceasing the transmitting of the EHF beaconing signal in response        to the received indication.

Paragraph 62: The method of paragraph 54, further including:

-   -   receiving an indication that a counterpart EHF communication        unit has received the transmitted EHF beaconing    -   powering on the circuitry and other circuitry in response to the        received indication.

Paragraph 63: A method for using an extremely high frequency (EHF)communication unit to listen for an EHF beaconing signal, the EHFcommunication unit including a timer and circuitry operative to receivethe EHF beaconing signal, the method including:

-   -   activating the timer in response to the EHF communication unit        entering a listen state, wherein the timer is operative to        provide a constant listen pulse once a cycle period to        periodically wake up the circuitry that receives EHF signals;    -   waking up the circuitry in response to the constant listen pulse        provided by the timer;    -   determining whether at least one EHF beaconing signal was        received during the constant listen pulse;    -   shutting down the circuitry if it is determined that no EHF        signal was received during the constant listen pulse; and    -   repeating a sequence including the waking up, the monitoring,        the determining, and the shutting down until the EHF        communication unit is instructed to cease monitoring for the EHF        beaconing signals.

Paragraph 64: The method of paragraph 63, wherein the EHF beaconingsignal is an EHF contactless signal including a logic value of HIGH.

Paragraph 65: The method of paragraph 63, further including:

-   -   transitioning to another state when it is determined that the        EHF beaconing signal is received during the constant listen        period.

Paragraph 66: The method of paragraph 65, wherein the other state is alink training state.

Paragraph 67: The method of paragraph 63, wherein the timer operatesaccording to a clock speed, wherein the constant listen period is basedon a first number of clock cycles and the cycle period is based on asecond number of clock cycles, wherein the second number of clock cyclesis larger than the first number of clock cycles.

Paragraph 68: The method of paragraph 67, wherein the timer operatesaccording to a selected one of a plurality of different clock speeds,wherein the constant listen period and the cycle period change based onthe selected clock speed.

Paragraph 69: The method of paragraph 67, wherein the first number ofclock cycles is a multiple of a third number of clock cycles thatdefines a cycle period of the EHF beaconing signal.

Paragraph 70: The method of paragraph 63, wherein the EHF communicationunit transitions from the listen state to an attentive state in responseto the constant listen pulse.

Paragraph 71: The method of paragraph 70, wherein the EHF communicationunit remains in the attentive state until at least one of the constantlisten period ends and it is determined that the EHF beacon signal isreceived during the constant listen period.

Paragraph 72: The method of paragraph 63, wherein the EHF communicationunit cycles through at least two states before re-entering into thelisten state.

Paragraph 73: The method of paragraph 63, wherein the at least twostates comprise a transmitter/receiver check state and an attentivestate.

Paragraph 74: The method of paragraph 73, wherein the received EHFbeaconing signal is an unsecured EHF signal.

Paragraph 75: The method of paragraph 63, further including:

-   -   communicating with another EHF communication unit when it is        determined that the EHF beaconing signal is received during the        constant listen period.

Paragraph 76: The method of paragraph 75, wherein the EHF communicationunit communicates with the other EHF communication unit by driving a pinthat is coupled to the other EHF communication unit via a wired path.

Paragraph 77: A first apparatus including:

-   -   an extremely high frequency (EHF) transceiver; and    -   control circuitry coupled to the EHF transceiver, the control        circuitry operative to:        -   control establishment of an EHF communications link with a            second apparatus by executing a state machine that tracks a            state of the first apparatus by transitioning through a            plurality of states in response to satisfaction of any one            of a plurality of conditions; and        -   selectively execute one of a beaconing cycle and a listening            cycle based on a configuration of the first apparatus,            wherein the beaconing cycle is executed if the configuration            is a transmitter configuration, and wherein the listening            cycle is executed if the configuration is a receiver            configuration.

Paragraph 78: The first apparatus of paragraph 77, wherein when thebeaconing cycle is selectively executed, the control circuitry isfurther operative to:

-   -   transmit, using the EHF transceiver, an EHF beaconing signal on        a periodic basis.

Paragraph 79: The first apparatus of paragraph 78, wherein the controlcircuitry is further operative to:

-   -   monitor a plurality of communication nodes for at least one        signal that indicates that one of the conditions has been        satisfied; and    -   cease using the EHF transceiver to transmit the EHF beaconing        signal in response to the at least one monitored signal.

Paragraph 80: The first apparatus of paragraph 77, wherein when thelistening cycle is selectively executed, the control circuitry isfurther operative to:

-   -   monitor the EHF transceiver on a periodic basis to determine        whether an ERE signal has been received.

Paragraph 81: The first apparatus of paragraph 80, wherein the controlcircuitry is further operative to:

-   -   cause the state machine to transition to a new state when the        EHF signal is received.

Paragraph 82: The first apparatus of paragraph 80, wherein the controlcircuitry is further operative to:

-   -   provide at least one signal on at least one of a plurality of        communication nodes when one of the conditions is satisfied.

Paragraph 83: The first apparatus of paragraph 77, further including atimer that operates according to a clock cycle and provides a pulse oncea period to periodically wake up the EHF transceiver.

Paragraph 84: The first apparatus of paragraph 83, wherein when thelistening cycle is selectively executed, the pulse spans a first numberof clock cycles and the period spans a second number of clock cycles,and wherein when the beaconing cycle is selectively executed, the pulseis held high for a fixed period of time and the period spans a thirdnumber of clock cycles, wherein the third number is a fraction of thefirst number, and wherein the second number is greater than the secondnumber.

Paragraph 85: The first apparatus of paragraph 83, wherein when thebeaconing cycle is selectively executed, the control circuitry isfurther operative to:

-   -   wake up the EHF transceiver in response to the pulse provided by        the timer;    -   transmit, from the EHF transceiver, the EHF beaconing signal for        a fixed time duration;    -   shut down the EHF transceiver after the fixed time duration has        elapsed; and    -   repeat a sequence including the wake up, the transmit, and the        shut down until the state machine transitions to a new state.

Paragraph 86: The first apparatus of paragraph 83, wherein when thelistening cycle is selectively executed, the control circuitry isfurther operative to:

-   -   wake up the circuitry in response to the pulse provided by the        timer;    -   monitor the EHF transceiver for EHF signals being received        during the pulse;    -   determine whether at least one EHF signal was received during        the pulse;    -   shut down the circuitry if it is determined that no EHF signal        was received during the pulse; and    -   repeat a sequence including the wake up, the monitor, the        determine, and the shut down.

Paragraph 87: A method for communicating a capabilities message betweenextremely high frequency (EHF) communication units, the methodincluding:

-   -   running a clock that has a clock cycle;    -   responsive to entering into a capabilities message state,        transmitting a repeating stream of messages via an EHF        transceiver,    -   wherein each message comprises a header field and a plurality of        message fields, the header field defining a start of each        message, and wherein each field is encoded with at least one        pulse-width-coded (PWC) symbol that is serialized according to        the clock such that one of 1-level EHF signal and a 0-level EHF        signal is associated with each clock cycle.

Paragraph 88: The method of paragraph 87, wherein each symbol spans afixed number of clock cycles, begins with a rising edge, ends with afalling edge, and terminates with a 0-level EHF signal.

Paragraph 89: The method of paragraph 88, wherein a logic 0 symbolcomprises between 1 and 3 1-level EHF signals.

Paragraph 90: The method of paragraph 88, wherein a logic 1 symbolcomprises between 7 and 11 1-level EHF signals.

Paragraph 91: The method of paragraph 88, where a header symbolcomprises between 4 and 6 1-level EHF signals.

Paragraph 92: The method of paragraph 87, wherein the transmittingcomprises:

-   -   inserting at least one gap cycle in between the repeated        messages, wherein a gap cycle is expressed as a 0-level EHF

Paragraph 93: The method of paragraph 87, wherein the header fieldcomprises at least one header symbol.

Paragraph 94: The method of paragraph 87, wherein each message fieldcomprises any combination of logic 0 and logic 1 symbols.

Paragraph 95: The method of paragraph 87, wherein at least one of themessage fields is populated with at least one symbol based on a state ofat least one of a plurality of pins.

Paragraph 96: The method of paragraph 87, wherein at least one of themessage fields is populated with at least one symbol based on datastored within the EHF communication unit.

Paragraph 97: The method of paragraph 87, further including:

-   -   obtaining the states of a plurality of pins;    -   determining an operating mode based on the obtained states; and    -   using symbols indicative of the determined operating mode in one        of the message fields.

Paragraph 98: The method of paragraph 87, further including:

-   -   retrieving message data from storage; and    -   using symbols indicative of the retrieved message data in one of        the message fields.

Paragraph 99: The method of paragraph 87, further including:

-   -   receiving an indication that another EHF communication unit has        received the message; and    -   instructing the state machine to transition to a new state in        response to the received indication that the other EHF        communication unit has received the message.

Paragraph 100: The method of paragraph 87, further including:

-   -   instructing the state machine to transition to a beaconing state        if no indication is received within a fixed period of time that        indicates that another EHF communication unit has received the        message.

Paragraph 101: A method for using a first extremely high frequency (EHF)communication unit to validate a capabilities message, the methodincluding:

-   -   receiving a counterpart capabilities message via an EHF        transceiver from a second EHF communication unit, wherein each        message comprises a header field and a plurality of counterpart        message fields, the header field defining a start of each        message, and the counterpart message fields defining parameters        of the counterpart device;    -   retrieving a local capabilities message from the first EHF        communication unit, the local capabilities message including a        plurality of local message fields; and    -   comparing at least one counterpart message field to an        equivalent local message field to validate the received        counterpart capabilities message.

Paragraph 102: The method of paragraph 101, further including:

-   -   determining whether to validate the counterpart message; and    -   instructing the first EHF communication unit to transition to a        new state when it is determined that the counterpart message is        validated.

Paragraph 103: The method of paragraph 102, further including:

-   -   providing at least one signal on at least one of a plurality of        communication nodes when the first EHF communication unit        transitions to the new state.

Paragraph 104: The method of paragraph 101, further including:

-   -   validating the counterpart message, wherein the validated        counterpart message identified a data transport mode; and    -   configuring the first EHF communication unit to process received        EFH signals according to the identified data transport mode.

Paragraph 105: The method of paragraph 101, wherein the at least onecounterpart message field and the equivalent local message field arevendor identification fields, the method further including:

-   -   rejecting the counterpart capabilities message if the contents        of the vendor identification fields are not the same; and    -   advancing acceptance of the capabilities message if the contents        of the vendor identification fields are the same.

Paragraph 106: The method of paragraph 101, wherein the at least onecounterpart message field and the equivalent local message field aredata transport mode fields, the method further including:

-   -   rejecting the counterpart capabilities message if the contents        of the data transport mode fields are not validated; and    -   advancing acceptance of the capabilities message if the contents        of the data transport mode fields are validated.

Paragraph 107: The method of paragraph 101, wherein the at least onecounterpart message field and the equivalent local message field aredata transport mode fields, wherein the counterpart message fieldincludes a counterpart USB mode and the local message field includes alocal USB mode, the method further including:

-   -   comparing the counterpart USB mode to the local USB mode to        determine validity of the counterpart capabilities message.

Paragraph 108: The method of paragraph 101, wherein the at least onecounterpart message field and the equivalent local message field are USBcode fields, wherein the counterpart message field includes acounterpart USB code and the local message field includes a local USBcode, the method further including:

-   -   comparing the counterpart USB code to the local USB code; and    -   performing an action based on the comparison of the USB codes.

Paragraph 109: The method of paragraph 108, wherein performing theaction comprises invalidating the counterpart capabilities message.

Paragraph 110: The method of paragraph 108, wherein performing theaction comprises validating the counterpart capabilities message.

Paragraph 111: The method of paragraph 108, wherein performing theaction comprises:

-   -   validating the counterpart capabilities message; and    -   driving a configuration pin of the EHF communication unit to one        of a logic 1 state and a logic 0 state.

Paragraph 112: A first apparatus including:

-   -   an extremely high frequency (EHF) transceiver; and    -   control circuitry coupled to the EHF transceiver, the control        circuitry operative to:        -   control establishment of an EHF communications link with a            second apparatus by executing a state machine that tracks a            state of the first apparatus by transitioning through a            plurality of states in response to satisfaction of any one            of a plurality of conditions; and        -   selectively execute one of a transmission of a capabilities            message and a validation of a received capabilities message            based on a configuration of the first apparatus, wherein the            transmission of the capabilities message is executed if the            configuration is a transmitter configuration, and wherein            the validation of the received capabilities message is            executed if the configuration is a receiver configuration.

Paragraph 113: The first apparatus of paragraph 112, wherein when thetransmission of the capabilities message is selected, the controlcircuitry is operative to:

-   -   instruct the EHF transceiver to contactlessly communicate the        capabilities message.

Paragraph 114: The first apparatus of paragraph 112, further including aclock that operates according to a clock cycle, wherein when thetransmission of the capabilities message is selected, the capabilitiesmessage comprises a header field and a plurality of message fields, theheader field defining a start of each message, and wherein each field isencoded with at least one pulse-width-coded (PWC) symbol that isserialized according to the clock such that one of 1-level EHF signaland a 0-level EHF signal is associated with each clock cycle.

Paragraph 115: The first apparatus of paragraph 114, wherein each symbolspans a fixed number of clock cycles, begins with a rising edge, endswith a falling edge, and terminates with a 0-level EHF signal.

Paragraph 116: The first apparatus of paragraph 114, further including aplurality of pins, wherein the control circuitry is operative to:

-   -   evaluate a state on at least one of the pins to ascertain a data        transport mode; and    -   encode one of the message fields with symbols that identify the        data transport mode.

Paragraph 117: The first apparatus of paragraph 114, further includingdata storage that stores data, wherein the control circuitry isoperative to:

-   -   access the data storage to obtain the data; and    -   encode one of the message fields with symbols that correspond to        the data.

Paragraph 118: The first apparatus of paragraph 114, wherein the controlcircuitry is operative to:

-   -   identify a USB mode of operation; and    -   encode one the message fields with symbols that correspond to        the identified USB mode of operation.

Paragraph 119: The first apparatus of paragraph 114, wherein the controlcircuitry is operative to:

-   -   instruct the EHF transceiver to transmit the selected one of the        1-level EHF signal and the 0-level EHF signal.

Paragraph 120: The first apparatus of paragraph 114, further includingat least one control pin, wherein the control circuitry is operative to:

-   -   monitor the at least one control pin for a signal that indicates        that one of the conditions has been satisfied; and    -   cease transmitting the capabilities message in response to the        monitored signal.

Paragraph 121: The first apparatus of paragraph 112, wherein when thevalidation of a received capabilities message is being executed, thecontrol circuitry is operative to:

-   -   process the received capabilities message, wherein the received        capabilities message comprises a header field and a plurality of        received message fields, the header field defining a start of        the message, and the received message fields defining parameters        of a counterpart EHF communication unit;    -   retrieve a local capabilities message from the first EHF        communication unit, the local capabilities message including a        plurality of local message fields; and    -   comparing at least one received message field to an equivalent        local message field to validate the received capabilities        message.

Paragraph 122: The first apparatus of paragraph 121, wherein the controlcircuitry is further operative to:

-   -   determine whether to validate the received message; and    -   instructing the first EHF communication unit to transition to a        new state when it is determined that the received message is        validated.

Paragraph 123: The first apparatus of paragraph 121, further including aplurality of configuration pins, wherein the control circuitry isoperative to:

-   -   evaluate a state on each of the configuration pins to ascertain        a local data transport mode; and    -   validate whether the local data transport mode works with a        received data transport mode of the received capabilities        message.

Paragraph 124: The apparatus of paragraph 123, wherein the controlcircuitry is operative to:

-   -   process data received via the EHF transceiver according to the        local data transport mode when it has been validated that it        will work with the received data transport mode.

Paragraph 125: The apparatus of paragraph 121, further including aplurality of control pins, wherein the control circuitry is operativeto:

-   -   assert a signal on at least one of the control pins in response        to a determination that the receive capabilities message is        validated.

Paragraph 126: An first apparatus including:

-   -   an extremely high frequency (EHF) transceiver; and    -   control circuitry coupled to the first EHF transceiver, the        control circuitry operative to:        -   control establishment of an EHF communications link with a            second apparatus by executing a state machine that tracks a            state of the first apparatus by transitioning through a            plurality of states in response to satisfaction of any one            of a plurality of conditions; and        -   selectively execute one of a transmission of a link training            pattern and a calibration of at least one parameter based on            a configuration of the first apparatus, wherein the            transmission of the link training pattern is executed if the            configuration is a transmitter configuration, and wherein            the calibration of at least one parameter is executed if the            configuration is a receiver configuration.

Paragraph 127: The apparatus of paragraph 126, wherein the link trainingpattern comprises a repeating pattern of HIGH and LOW bits.

Paragraph 128: The apparatus of paragraph 126, further including areference signal parameter, wherein when the transmission of the linktraining pattern is being executed, the control circuitry is operativeto:

-   -   base an amplitude of the link training pattern on the reference        signal parameter.

Paragraph 129: The apparatus of paragraph 128, wherein the referencesignal parameter is a reference voltage level derived from a bandgap.

Paragraph 130: The apparatus of paragraph 126, wherein when thetransmission of the link training pattern is being executed, the controlcircuitry is operative to:

-   -   selectively map the link training pattern to one a full carrier        for a logic 1 state, a partial carrier for a logic 0 state, and        no carrier for an idle state.

Paragraph 131: The apparatus of paragraph 130, wherein the partialcarrier is a percentage of the full carrier.

Paragraph 132: The apparatus of paragraph 126, wherein when thecalibration of at least one parameter is being executed, the controlcircuitry is operative to:

-   -   process a link training pattern received via the EHF        transceiver, wherein the received link training pattern        comprises a logic 1 state, a logic 0 state, and an idle state,        and wherein each state is represented by a different carrier        amplitude;    -   differentiate among the different carrier amplitudes in the        processed link training pattern; and    -   associate each state with one of the different carrier        amplitudes.

Paragraph 133: The apparatus of paragraph 126, wherein when thecalibration of at least one parameter is being executed, the controlcircuitry is operative to:

-   -   track an amplitude of a received signal envelope; and    -   calibrate the tracked amplitude to one of a logic 1 state, a        logic 0 state, and an idle state.

Paragraph 134: The apparatus of paragraph 126, wherein when thecalibration of at least one parameter is being executed, the controlcircuitry is operative to:

-   -   use a slicer to sample received EHF signals, wherein the slicer        samples the received EHF signals based on a clock; and    -   calibrate a phase angle of the clock to optimize sampling of the        received EHF signals.

Paragraph 135: A method for using an extremely high frequency (EHF)communication unit to transmit a keep alive signal, the EHFcommunication unit including a timer and circuitry operative to transmitthe keep alive signal, the method including:

-   -   activating the timer in response to the EHF communication unit        entering an idle state, wherein the timer is operative to        provide a pulse once a period to periodically wake up the        circuitry that transmits the keep alive signal;    -   waking up the circuitry in response to the pulse provided by the        timer;    -   transmitting, from the circuitry, the keep alive signal;    -   shutting down the circuitry; and    -   repeating a sequence including the waking up, the transmitting,        and the shutting down.

Paragraph 136: The method of paragraph 135, further including:

-   -   monitoring whether any data is received on an input buffer of        the EHF communication unit; and    -   transitioning to a data transport state in response to a        determination that data has been monitored as received on the        input buffer.

Paragraph 137: The method of paragraph 136, further including:

-   -   powering on the circuitry in response to the transitioning to        the data transport state.

Paragraph 138: The method of paragraph 135, further including:

-   -   monitoring at least one control pin to determine whether to        execute a state change transition;    -   transitioning to a beacon/listen state in response to a        determination to execute a state change determination.

Paragraph 139: The method of paragraph 138, wherein the monitoringcomprises monitoring whether a signal on one of the control pins hasgone LOW.

Paragraph 140: The method of paragraph 138, wherein the monitoringcomprises monitoring whether there has been no activity on one of thecontrol pins for at least a period of time.

Paragraph 141: The method of paragraph 135, wherein the keep alive pulseis operative to prevent a counterpart EHF communication unit fromtransitioning away from its idle state, wherein counterpart EHFcommunication unit receives the keep alive pulse via its EHFtransceiver.

Paragraph 142: A method for using a first extremely high frequency (EHF)communication unit, the method including:

-   -   entering the first EHF communication unit into a power savings        state of operation after an extremely high frequency (EHF)        communications link has been established with a second EHF        communication unit, wherein when the first EHF communication        unit is operating in the power saving mode, the method further        including:        -   power cycling EHF transceiver circuitry ON and OFF;        -   monitoring whether any EHF signals are being received via            the EHF transceiver circuitry when the EHF transceiver            circuitry is ON; and        -   determining if received EHF signals are indicative of one of            a first pulse and a second pulse,        -   wherein in determining that the received EHF signals are            indicative of the first pulse, transitioning the first EHF            communication unit to a first state; and        -   wherein in determining that the received EHF signals are            indicative of the second pulse, instructing the first EHF            communication unit to continue operating in the power            savings state of operation.

Paragraph 143: The method of paragraph 142, wherein the first state is adata transport state.

Paragraph 144: The method of paragraph 142, wherein the instructing thefirst EHF communication unit to continue operating in the power savingsstate of operation comprises:

-   -   resetting a time out timer; and    -   power cycling the EHF transceiver OFF.

Paragraph 145: The method of paragraph 142, wherein when no EHF signalsare received when the EHF transceiver is ON, the method furtherincluding:

-   -   determining whether a time out timer has expired.

Paragraph 146: The method of paragraph 145, further including:

-   -   in response to determining that the time out timer has expired,        transitioning the EHF communication unit to a second state.

Paragraph 147: The method of paragraph 146, wherein the second state isa beacon/listen state.

Paragraph 148: The method of paragraph 142, wherein the first pulsecomprises a burst of logical 1s and 0s that exceeds a first burstlength.

Paragraph 149: The method of paragraph 142, wherein the second pulsecomprises a burst of logical 1s that falls within a fixed range burstlength.

Paragraph 150: A first apparatus including:

-   -   an extremely high frequency (EHF) transceiver; and    -   control circuitry coupled to the EHF transceiver, the control        circuitry operative to:        -   control establishment of an EHF communications link with a            second apparatus by executing a state machine that tracks a            state of the first apparatus by transitioning through a            plurality of states in response to satisfaction of any one            of a plurality of conditions;        -   establish the EHF communication link with the apparatus to            selectively enable one of transmission and reception of            data;        -   after the EHF communication link with the apparatus is            established, monitor an absence of data being communicated            over the EHF communication link; and        -   enter into a power savings state in response to the            monitored absence of data being communicated over the EHF            communication link until the state machine transitions to a            new state.

Paragraph 151: The first apparatus of paragraph 150, wherein when in thepower savings state, the control circuitry is further operative to:

-   -   power cycle the EHF transceiver ON and OFF;    -   monitor whether any EHF signals are being received via the EHF        transceiver circuitry when the EHF transceiver circuitry is ON;        and    -   determine if received EHF signals are indicative of one of a        first pulse and a second pulse,    -   wherein in determining that the received EHF signals are        indicative of the first pulse, transition the EHF communication        unit to a first state; and    -   wherein in determining that the received EHF signals are        indicative of the second pulse, instruct the EHF communication        unit to continue operating in the power savings state of        operation.

Paragraph 152: The first apparatus of paragraph 151, wherein the firststate is a data transport state.

Paragraph 153: The first apparatus of paragraph 151, wherein in responseto determining that the received EHF signals are indicative of thesecond pulse the control circuitry is operative to:

-   -   reset a time out timer in response; and    -   power cycle the EHF transceiver OFF.

Paragraph 154: The first apparatus of paragraph 151, wherein when no EHFsignals are received when the EHF transceiver is ON, the controlcircuitry is operative to:

-   -   determine whether a time out timer has expired;    -   transition the apparatus to a second state in response to the        determination that the time out timer has expired.

Paragraph 155: The first apparatus of paragraph 154, wherein the secondstate is a beacon/listen state.

Paragraph 156: The first apparatus of paragraph 150, wherein when in thepower savings state, the control circuitry is further operative to:

-   -   activate a timer, wherein the timer is operative to provide a        pulse once a period to periodically wake up the EHF transceiver;    -   wake up the EHF transceiver in response to the pulse provided by        the timer;    -   transmit, from the EHF transceiver, the keep alive signal; and    -   shut down the EHF transceiver.

Paragraph 157: The first apparatus of paragraph 156, wherein the controlcircuitry is further operative to:

-   -   monitor whether any data is received on an input buffer of the        EHF communication unit; and    -   transition to a data transport state in response to a        determination that data has been monitored as received on the        input buffer.

Paragraph 158: The first apparatus of paragraph 156, wherein when in thepower savings state, the control circuitry is further operative to:

-   -   monitor at least one control pin to determine whether to execute        a state change transition;    -   transition to a beacon/listen state in response to a        determination to execute a state change determination.

Paragraph 159: The first apparatus of paragraph 156, wherein the keepalive pulse is operative to prevent the other apparatus fromtransitioning away from its power savings state, wherein the secondapparatus receives the keep alive pulse via its EHF transceiver.

Paragraph 160: A first contactless communications transceiver unit(CCTU) for use in establishing a contactless communications link with asecond CCTU, the first CCTU including:

-   -   a transducer for selectively transmitting and receiving        extremely high frequency (EHF) contactless signals; and    -   circuitry operative to:        -   execute a first CCTU state machine that tracks a state of            the first CCTU during the establishment of the contactless            communications link, wherein the state machine transitions            through a plurality of states in response to satisfaction of            any one of a plurality of conditions;        -   for at least one of the plurality of states, instruct the            transducer to alternate between transmitting EHF contactless            signals to the second CCTU and monitoring for EHF            contactless signals transmitted by the second CCTU to            determine whether one of the conditions is satisfied.

Paragraph 161: The first CCTU of paragraph 160, wherein the circuitry isoperative to:

-   -   transmit a EHF signal for a first time period; and    -   after the first time period expires, monitor for a EHF response        signal from the second CCTU for a second time period.

Paragraph 162: The first CCTU of paragraph 161, wherein the EHF signalcomprises an EHF beaconing signal.

Paragraph 163: The first CCTU of paragraph 161, wherein the EHF signalcomprises a link training signal.

Paragraph 164: The first CCTU of paragraph 161, wherein the EHF signalcomprises a capabilities message signal.

Paragraph 165: The first CCTU of paragraph 161, wherein the circuitry isoperative to:

-   -   receive the EHF response signal during the second time period;        and    -   determine that the received EHF response signal satisfies one of        the conditions.

Paragraph 166: The first CCTU of paragraph 160, wherein the circuitry isoperative to:

-   -   monitor for a EHF signal being transmitted by the second CCTU        for a third time period.

Paragraph 167: The first CCTU of paragraph 166, wherein the monitoredEHF signal comprises a beaconing EHF signal.

Paragraph 168: The first CCTU of paragraph 166, wherein the monitoredEHF signal comprises a link training EHF signal.

Paragraph 169: The first CCTU of paragraph 166, wherein the monitoredEHF signal comprises a capabilities message EHF signal.

Paragraph 170: The first CCTU of paragraph 166, wherein the circuitry isoperative to;

-   -   receive the EHF signal during the third time period;    -   validate the EHF signal; and        after the third time period expires, transmit an EHF response        signal to the second CCTU if the received EHF signal is        validated.

It is believed that the disclosure set forth herein encompasses multipledistinct inventions with independent utility. While each of theseinventions has been disclosed in its preferred form, the specificembodiments thereof as disclosed and illustrated herein are not to beconsidered in a limiting sense as numerous variations are possible. Eachexample defines an embodiment disclosed in the foregoing disclosure, butany one example does not necessarily encompass all features orcombinations that may be eventually claimed. Where the descriptionrecites “a” or “a first” element or the equivalent thereof, suchdescription includes one or more such elements, neither requiring norexcluding two or more such elements. Further, ordinal indicators, suchas first, second or third, for identified elements are used todistinguish between the elements, and do not indicate a required orlimited number of such elements, and do not indicate a particularposition or order of such elements unless otherwise specifically stated.

Whereas many alterations and modifications of the present invention willno doubt become apparent to a person of ordinary skill in the art afterhaving read the foregoing description, it is to be understood that theparticular embodiments shown and described by way of illustration are inno way intended to be considered limiting. Therefore, reference to thedetails of the preferred embodiments is not intended to limit theirscope.

1.-38. (canceled)
 39. A method for using a first extremely highfrequency (EHF) communication unit, the method including: entering thefirst EHF communication unit into a power savings state of operationafter an extremely high frequency (EHF) communications link has beenestablished with a second EHF communication unit, wherein when the firstEHF communication unit is operating in the power saving mode, the methodfurther including: power cycling EHF transceiver circuitry ON and OFF;monitoring whether any EHF signals are being received via the EHFtransceiver circuitry when the EHF transceiver circuitry is ON; anddetermining if received EHF signals are indicative of one of a firstpulse and a second pulse, wherein in determining that the received EHFsignals are indicative of the first pulse, transitioning the first EHFcommunication unit to a first state; and wherein in determining that thereceived EHF signals are indicative of the second pulse, instructing thefirst EHF communication unit to continue operating in the power savingsstate of operation.
 40. The method of claim 39, wherein the first stateis a data transport state.
 41. The method of claim 39, wherein theinstructing the first EHF communication unit to continue operating inthe power savings state of operation comprises: resetting a time outtimer; and power cycling the EHF transceiver OFF.
 42. The method ofclaim 39, wherein when no EHF signals are received when the EHFtransceiver is ON, the method further including: determining whether atime out timer has expired.
 43. The method of claim 42, furtherincluding: in response to determining that the time out timer hasexpired, transitioning the EHF communication unit to a second state. 44.The method of claim 43, wherein the second state is a beacon/listenstate.
 45. The method of claim 39, wherein the first pulse comprises aburst of logical 1s and 0s that exceeds a first burst length.
 46. Themethod of claim 39, wherein the second pulse comprises a burst oflogical 1's that falls within a fixed range burst length.
 47. A firstapparatus including: an extremely high frequency (EHF) transceiver; andcontrol circuitry coupled to the EHF transceiver, the control circuitryoperative to: control establishment of an EHF communications link with asecond apparatus by executing a state machine that tracks a state of thefirst apparatus by transitioning through a plurality of states inresponse to satisfaction of any one of a plurality of conditions;establish the EHF communication link with the apparatus to selectivelyenable one of transmission and reception of data; after the EHFcommunication link with the apparatus is established, monitor an absenceof data being communicated over the EHF communication link; and enterinto a power savings state in response to the monitored absence of databeing communicated over the EHF communication link until the statemachine transitions to a new state.
 48. The first apparatus of claim 47,wherein when in the power savings state, the control circuitry isfurther operative to: power cycle the EHF transceiver ON and OFF;monitor whether any EHF signals are being received via the EHFtransceiver when the EHF transceiver circuitry is ON; and determine ifreceived EHF signals are indicative of one of a first pulse and a secondpulse, wherein in determining that the received EHF signals areindicative of the first pulse, transition the EHF communication unit toa first state; and wherein in determining that the received EHF signalsare indicative of the second pulse, instruct the EHF transceiver tocontinue operating in the power savings state of operation.
 49. Thefirst apparatus of claim 48, wherein the first state is a data transportstate.
 50. The first apparatus of claim 48, wherein in response todetermining that the received EHF signals are indicative of the secondpulse the control circuitry is operative to: reset a time out timer inresponse; and power cycle the EHF transceiver OFF.
 51. The firstapparatus of claim 48, wherein when no EHF signals are received when theEHF transceiver is ON, the control circuitry is operative to: determinewhether a time out timer has expired; and transition the apparatus to asecond state in response to the determination that the time out timerhas expired.
 52. The first apparatus of claim 51, wherein the secondstate is a beacon/listen state.
 53. The first apparatus of claim 47,wherein when in the power savings state, the control circuitry isfurther operative to: activate a timer, wherein the timer is operativeto provide a pulse once a period to periodically wake up the EHFtransceiver; wake up the EHF transceiver in response to the pulseprovided by the timer; transmit, from the EHF transceiver, a keep alivesignal; and shut down the EHF transceiver.
 54. The first apparatus ofclaim 53, wherein the control circuitry is further operative to: monitorwhether any data is received on an input buffer of the EHF transceiver;and transition to a data transport state in response to a determinationthat data has been monitored as received on the input buffer.
 55. Thefirst apparatus of claim 53, wherein when in the power savings state,the control circuitry is further operative to: monitor at least onecontrol pin to determine whether to execute a state change transition;and transition to a beacon/listen state in response to a determinationto execute a state change determination.
 56. The first apparatus ofclaim 53, wherein the keep alive pulse is operative to prevent the otherapparatus from transitioning away from its power savings state, whereinthe second apparatus receives the keep alive pulse via its EHFtransceiver.